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ADVICE WANTED!   July 26, 2003
www.findstone.com   info@findstone.com

 Slate Cure / Clean 

Problems: streaks, white marks, stains, discoloration, turned grey, dull, want wet look, non uniform color, wax removal, scratches, flaking

Most people personify an inanimate object only when it fails to do something they expect or it does something they don't expect.
My opinion about any stone material is that it is all good. How people use it is what can be construed as bad.
Some slates are too soft and absorptive for a wet area. Natural cleft material will never be flat. Honed slate will scratch. If people understand what they are buying and understand where they are putting it then slate is not usually a problem. Steven

Q 5448:
My problem is two fold. First, the previous owner installed the slate floor in the bathroom with the toilet in place and where there was a gap (any where from a 1/2" to 1") he filled in with colored chalk. I want to repair this. If I do not or cannot remove all the chalk, will this effect my grout joints? Second, where the slate met the walls there is paint on the slate. Can I use ZIP STRIP (for paint and clear finishes) to remove this, without damage to the slate? Thanks for your time. Frank, July 23, Reply

Q 5445: Have installed brazilian cinza slate tiles in the kitchen (cleft finish) and same material in honed slab for the countertop. The kitchen is very small (140 sq feet) and the countertop is approx 7 feet with cutouts for sink and cooktop. Neither has been sealed and both have developed some stains. the countertop stains are food based and the floor are grease, garden soil, paint. I think I should seal both. How do I first clean the surfaces, and then what sealer would you recommend for each surface. I have an electric power washer and also a floor machine. thank you-- Naresh, July 23, Reply

Q 5444: We have a concrete base on a second level outdoor patio. Two years later, the slate is buckling up. Thin set was used to attach the slate to the concrete and grouting between the slate tiles. When you tap on the tiles, there seems to be a hollow sound underneath? Does this mean that it is loose? I’ve been told it does not. A outdoor waterproof sealer was used on the tile when the patio was built. How can I fix these tiles that have become loose and how can I prevent it from happening again? Many thanks. Howard, July 23, Reply

R1: First question is where did the slate come from? Was the bottom gauged? How thick was the material? And what is the drainage system like? Debra

Q 5443: I have a black slate counter top that came out of a doctors office and it looks like it has never been sealed, I want to put it outside on my deck and was wondering what would be the best sealer to use to keep it from getting stained and to bring out some shine?. Thanx, Frank, July 23, Reply

Q 5429: I am a builder and used slate on some decks on two houses which are above living areas. I used GlazeNSeal Multipurpose Sealer (2 coats) but I am experiencing a lot of efflorescence pushing out at the edges of the decks and getting onto the shingle siding. The decks were constructed with a pitch to the gutters and most of the effloresence goes into the gutters but I did not curb the edges (mistake!) and during heavy rains there is water and calcium salts pushed out the sides. I am looking for the best sealer to minimize the amount of water that pentrates the slate and grout lines. I know I can't stop it but if I can decrease the water volume it will hopefully run down into the gutters and not out the sides. Any recommendations on products??? I would appreciate your opinion. Thanks! Dan, July 23, Reply

R1: Miracle Sealer has a good sealer called Mira matt which should solve your problem Willard

Q 5422: Hi, I have a problem with my bathroom floor.......it is slate. I actually have slate in the kitchen and hall as well although it is fine. In the bathroom it appears that water has got underneath the sealer (I'm guessing). It is virtually white (my slate is very dark). It looks okay when you first mop it but when it dries the white patches come back. It is very frustrating. Can you sand slate? If you can, would the white patches just reappear with time or do you think that the sealing wasn't done properly. Looking forward to you advice. Sharyn, July 23, Reply

R1: Strip the sealer with acidtone from home depot (nail polish remover) or solvent and re-seal with good acrylic sealer or acrylic floor finish 3 coats Willard

Q 5420: How many types of bonding are there for marble? How many types of bonding are there for slate? July 22, Reply
R1: For marble there are two popular bonding agents, which are epoxy and two-part acrylic glue. The former (more expensive) is more apt for outdoor installations. The latter can be successfully used in indoor installations. About slate I don't know anything and I don't want to know anything! :) Ciao and good luck, Maurizio, Expert Panelist
R2: What do you mean by bonding? It is a counter top, floor or landscaping application? Honed or natural cleft? Debra


R1: Slate is cut with diamond blades and water. Debra

Q 5417: I too am trying to get some scratches from slate - no more than a fraction of a mm deep. I've tried sandpaper, glasspaper, aluminium oxide sanding disk, slow speed, high speed, with and without water but all I remove is a microscopic amount of slate dust - I could be there for days ! Any ideas where I am going wrong - are some types of slate much harder than others (these are just common or garden wall tiles from the DIY store - no idea of their original source. Thanks Stephen, July 22, Reply

R1: Likely the softness is your problem. Usually, if a scratch occurs on a slate tile,, if it is natural cleft, you simply oil the scratch and it falls in line with the rest of the natural cleft. If the surface has been honed. Further minor honing and sealing should do it. Slate, like any other material can either be of low quality or high quality…Origin usually is a good indicator. Does the slate have pyrite? These corrode and allow pits to form, etc. Many slates from Asian countries are very soft and need to be sealed every three months or so… Debra C. Donovan

Q 5416: My husband and i are planning on installing black slate tile in our foyer. This is a first for us, we have installed ceramic but never slate. Other than sealing it is the installation different? Also, we are planning on cutting the 4 corners off, and placing a 2x2 inch green slate sqare between each black tile. How difficult is it to cut the tile, do I use the same wet saw I would use if I were installing ceramic. Thanks for any advice you can provide. Rachel, July 22, Reply

R1: Install like ceramic. Just remember to seal once before applying grout. This will ensure that the grout washes off the slate if it accidentally gets onto the slate. Debra C. Donovan

Q 5415: My Mom has two slate covered back stoops. Some of the slate pieces are starting to come off. I would like to try and repair it for her. Any suggestions? Thank you in advance for your help. Diane, July 22, Reply

Q 5414: We are building a home and want to use slate for our large fireplace surround, entry, porch, and basement stair landing. Can I buy slate from Home Depot that will be good for these applications and what can I expect to pay for black (gray) slate? Do some of the stores have better prices than others? I can go to Dallas to buy. Thank You!!! Donna Lewis, July 22, Reply

R1: If you purchase Vermont or Canadian or UK slate, you will be in good geology. Debra

Q 5413: I live in Vancouver, and would like to install a 16x16 black slate tiles for my kitchen floor, mostly because I want black, I like the look of natural stone, and apparently slate is a not as slippery as when wet as ceramic tiles can be (which makes sense in a kitchen)
I have read many questions on the findstone site, and it has just confused me even more, so many conflicting answers.
Are there differences between slates (aside from colour) if I am looking for black slate, is black slate, black slate? Or are there some that are better than others? Do I just tell my flooring contractor that I want black slate, and let him go get it?
I do prefer a little more shine than slate offers, and one tile store showed me how a few coats of sealer can make the slate less dull, yet I have read many q&a on this site that leads me to think this is not necessarily so.Thank you Marie, July 22, Reply

Q 5411: My neighbor removed all the slate from her yard. They are irregular pieces. Most at least one inch thick. Can I install this as a kitchen floor? Thanks! Annemarie, July 22, Reply

R1: We offer gauged irregular slate flooring. Coming from outdoors, need to know where it came from. You will have weight issues and installation will be more challenging where the slate is not all the same thickness and the bottom will not be perfectly flat. Debra

Q 5410: I am contemplating changing my exposed aggregate patio by overlaying it with slate flagstones. I prefer not to use cement as some people do. Can I use the sand method? The patio is quite low versus the house so I've plenty of room to put more layers on it w/o it becoming too high. If I use the sand method, do I also use grout? [This email was prepared using voice recognition software rather than keyboarding; please disregard any formatting glitches or the like. Sara, July 22, Reply

Q 5408: I recently had an outdoor slate floor (black with a blue-ish tint) installed. It's about 300 sq ft. The tiles are 2 foot square and 1 inch thick and are set at 3/4 inch spacing finished with a dark colored outdoor grout. Shortly after the installers left and after a few rainfalls, I noticed that a white-ish film was developing in a pattern matching the rain runoff. It looks a bit like efflorescence, but might be coming from the grout?
In addition, I'd like the color of the floor to be a richer, deeper color. Maybe not so flat.
I've read about color enhancers, but don't know if I also need a sealer and if so, is it applied before or after the enhancer. Finally, with the enhancer do the job of sealing the grout or does that need something completely separate.Anyway, I'd appreciate your help in this dilemma.If pictures would help, I'd be happy to send them.Regards, Rick July 22, Reply

R1: The grout is likely causing the problem. The grout would need to be sealed. If you used a slate oil/sealer, it could do both jobs for you. but you need to ensure that the surface is truly dry. Is there good drainage from your base?. Concrete absorbs water and the moisture is coming from the bottom. Debra C.

Q 5407: I just purchased a house and the black slate floor is starting to turn white and the surface is flaking. It turns out that in 1997 the floor was stripped and then a "wet look" lacquer was applied. Since then it has had coats of sealer to help it shine. I want to remove all coatings and start over from the bare stone/slate.What should I use to remove these finishes and how should I proceed in sealing it to get the dark black and low gloss look, July 22, Reply

R1: Paint stripper would likely work. but could do damage to the grout. The slate can withstand any chemical (if it is a quality slate) The grout is your weak link. Debra C. Donovan

Q 5406: I am putting a raised stacked stone hearth at my fireplace and need suggestions for a hearth cap. I want a surface that I can sit on and maybe set a drink on (not too uneven). I love slate and have slate designs in my kitchen backsplash which is adjacent to my fireplace room.Would slate be appropriate? If not, any suggestions? Pam, July 22, Reply

Q 5403: Laid 1200 square feet of slate outside on porch and patio. Though the installation looks fine, the finished used on it (Aqua Mix Stone Enhancer) seems to have created a dull, grayish look that makes all the color in the slate disappear, particularly in the sunlight. A few tile installers have looked at it and said it's not supposed to look like this. I hate the "shiny" look and want it to be natural stone look but with more color and maybe only a bit of a sheen that picks up light. Any suggestions? Thanks. Ann, July 22, Reply

Q 5402: I am studying an interior design course and currently have to do a paper on interior use of marble and slates. I am having difficulty getting technical information and are wondering if you can help me. below is a list of the information I need. Composition (i.e. calcium carbonate etc and what type of rock it is i.e. I know marble is metamorphic) Hardness (rating i.e.. Marble is 3 for soft and an explanation - "can be easily scratched") Absorption rating and what it absorbs (water / oil?) Sealants type used and why Cleaning and maintenance (what is it cleaned with - how often)binding process (I have no idea what a binding process is, why, what is used, etc) Fire classification (I think they want this one so you know if you can use it in a kitchen or fire hearth - not sure - there must be some sort of rating) Thermal value Acoustical value I would very much appreciate it if you can help.Thank you in advance Kind Regards, Robert Ross, July 22, Reply
R1: Dear Robert Ross: And who said that miracles don't exist? Look, an interior designer to be who wants to now something different than color!! :)I do believe I can answer most of your questions. Gimme a holler at: info@findstone.com and get in touch with me. There's a little fee involved (as you will be told), but I'll be glad to help. Ciao and good luck,Maurizio, Expert Panelist

Q 5400: I have a concrete front porch. There are no cracks, but it is pitted in some areas. What tile would be appropriate for this space? Would 1/4" slate tiles work? What prep is needed prior to laying tiles or slate? I live in the north-east, so temperature change is a major factor. I have gotten conflicting information from the so called experts in the area. Your advice would be helpful. Thank you. Tracey, July 22, Reply

R1: We usually recommend thicker tiles for the exterior. This will help to protect the adhesive from condensation due to freeze/thaw cycles on sunny days. (Got this info from an old Italian tile person) Does make sense though. We have always suggested 1 -1.5 inches thick for exterior applications when wet laid and we have not had problems. Our stone has been freeze thaw tested, etc. Technical info on web site as well as installation info. Let me know if I can be of further service. Debra

Q 5404: I am building my first and last home. The overall look that I want is "rustic elegance." A full walk-out, poured concrete basement will be the center of attention. I want as low-maintenance as possible, and would sincerely appreciate your unbiased opinion. I like slate, stone, porcelain tile and granite. It seems your answers to most questions indicate that you prefer granite counter tops. How about the covering for the concrete floor? Granite or marble is too elegant for me here, so I would appreciate your suggestion for a care-free surface. Tim, July 22, Reply
R1: Dear Tim: Nothing is more care-free than porcelain tiles. What's also nice about them that they come in any type of "natural stone" looks. Ciao and good luck, Maurizio, Expert Panelist
R2: Have you considered a high quality slate.? Geology is very important when dealing with stone materials. North American slates are ranked as the best in the world along with those from the UK.

Once installated, only need to wash with water and vinegar. If you have infloor heating the slate hold the heat really well. We usually suggest a thicker slate tile for these floors. (Same price whether tile is ½” or anything up to 1.5” thick. And we custom cut the tiles to any size) Not affected by salt or sand or chemicals. Let me know if I can be of further service.Debra

R3: You need the real thing - which is slate flooring - the perfect rustic low maintenance flooring Willard

Q 5398: I am looking at a roof in Enid, Oklahoma that is claimed to be damaged from the build-up of about 3 inches of ice over it full area. Ice remained for about 2 weeks before completely melting. Its a 12:12 slope. Reported to be 100 year old slate from Illinois, installed about 5 to 10 years years ago. Do you have any articles that dicuss the type of damage expected from such an occurance, and any comments would be appreciated.Thanks, Jerry, July 22, Reply
Q 5397: what kind of sealant should I use for a slate floor? what kind of thinset? grout? Kathy, July 22, Reply

Q 5396: I am currently installing a new bathroom with slate floor and shower. How should I initially treat the slate, and how should I best maintain it? James, July 22, Reply

Q 5394: I ran across your website regarding questions from readers. I am considering of installing slate in my entry and into the family room. What is your opinion on slate for such rooms. Also, advice on the specific type of slate on should install for such high traffic area. Also, is there any special care, of applying a shield or etc, that I need to be concern with? Any information you provide will be most appreciative. Thanks, Mike, July 22, Reply

Q 5393: Could you possibly tell me what to use on slate tile floors?I need something to clean them .Thank you, Linda, July 22, Reply

Q 5391: Hey There! We own a 70's house with a raised black slate hearth. We've actually painted the white grout black...hope this is ok {it looks 100x's better}.The slate now just needs to be perked up with a little polish or sealant. What are your suggestions? signed, barb, July 22, Reply

Q 5389: I broke a slate back to a sink, how can i repair it and hold it back together. it was a clean brake from the top to the bottom.thanks nathan, July 22, Reply

Q 5388: I need to know what I should do to get crayola crayon markings off of the slate on my fireplace base. I've scrubbed with soap and water on a scrubber sponge but it didn't work. I'm afraid to use a harsh chemical. Please help! Thanks Andrea, July 22, Reply

Q 5387: I have a problem with my bathroom floor.......it is slate. I actually have slate in the kitchen and hall as well although it is fine. In the bathroom it appears that water has got underneath the sealer (I'm guessing). It is virtually white (my slate is very dark). It looks okay when you first mop it but when it dries the white patches come back. It is very frustrating. Can you sand slate? If you can, would the white patches just reappear with time or do you think that the sealing wasn't done properly. Looking forward to you advice. Sharyn, July 22, Reply

Q 5385: I have multi-colored slate tiles to install in a new powder room. I want to select the ones with the most colors on them. How do I tell what they will look like when sealed? If I put water on them will that give me a resonable facsimile of what it will look like sealed? Thanks H. July 22, Reply

R1: Yes Debra

Q 5384: I have found a fire place in my mother’s house which was built in the early 1920’s. I have enclosed some photos as I am wondering if you can identify what type of stone it is. It looks like marble however it could be some sort of granite or slate or something else. I would like to restore the fire place but without knowing what it is I cannot do anything. Can you please please help me? Kind Regards Silvana, July 22, Reply

Q 5383: I have been contacted to be an import agent of slate and other stone from India in to the U.S. I need information on everything about being an Import /Export agent. I would appreciate it if you would email me the information.Thank you, Nina, July 22, Reply
R1: Dear Nina: If you want to sell slate, you will need to get three things and three things only: 1. A manual on marketing. 2. A magic sentence. 3. A good pair of earplugs. Let me explain what I mean and how you will be using the three means I listed for you.The first one is pretty much self-explanatory: you've got to learn how to sell the stuff, and the more you will sell of it the more money you will be making! Of course you won't have much time left to learn about what the heck you're selling, but it really doesn't matter. In fact, you do NOT want to know! The second, which is the magic sentence that you MUST learn by heart is: "All you have to do is seal it!" (Whatever that means! but then again it's not necessary to understand that, either.) In fact, here comes the last and most important "accessory" to the whole business: the earplugs. When somebody will come back complaining about the beautiful stuff you sold to them, and also report that the sealer turned out to be only the trading of a problem for another one, by wearing your all too precious earplugs, you will get away from any possible trouble totally unscathed! It does work! Look at this very site: How many complains come in about slate every single day! I had to stop answering them because in most instances they were without a solution, and the slate merchants who are involved in this site complained very loudly about my "attitude", which was hurting their business. Fine, I said, let them solve their own problems! Did you ever see that happening? Not a chance! The earplugs are on all the time! :) Ciao and good luck,Maurizio, Expert Panelist
R2: If you want to sell slate, sell the geology of it. Slates coming from certain geologies are very soft and need to be sealed just about every month. Quality geology, as found in Canada, Vermont and UK are a lot less work. If installed properly, they are worry free. Problem is that low quality product is being dumped into our high end North American markets and the consumer needs to be educated about the different geologies and how that affects the performance of different slates. Most of the problems from slate consumers is that they likely purchased a very soft, low price imported slate. Debra

Q 5366: I've been seeing a lot of front stoop makeovers on television. Mostly, they cover the concrete with pretty slate. I would love to do this, but we're in Minnesota, and don't know if that is the best stone to use in this climate. I would certainly appreciate your advice! July 14, Reply

Q 5360: I am considering several stones for my kitchen countertops: brazilian green slate; a jura green German limestone; a black (with white veins) Italian limestone; and a grey Irish limestone. I know granite is probably the best choice for kitchen countertops, but I do not like granite. Can you comment on the pros and cons of the brazilian slate, vs. the limestones. I was also considering a Vermont slate, but it is significantly more expensive than the brazilain slate. Is it worth the price difference? Thanks in advance for your advice. Liz, July 14, Reply
R1: Dear Liz: In my opinion, none of the materials you listed is suitable for a busy kitchen countertop. Ciao and good luck, Maurizio, Expert Panelist
R2: We install 5 kitchen counter tops per week with brazilian Slate mostly honed or natural black which is more a dark grey but some green as well - it is very succesful and we cannot keep enough slab material in stock at the moment. We do both slate and lime stone in flooring and counter tops, Wilard
Q 5347: I have slate flooring on my floors in the foyer, hall, 1/2 bath and wet bar room. I have no idea what kind it is, but the base color is dark grey with some green in it. It's dull, and lifeless. Is there any sealer that will make it shine like glass? Would any of the interior concrete sealers that are buff-ed to a high gloss work? Not only is this same slate on the floors that run throughout this house but the remodel contractor that I was told did the work 10 years ago put it on the wet bar counter top and back splash. When its wet it's it looks great, but dries dull. Help me. All the natural stone stores I've been to here in Cleveland Ohio have told be there is nothing that can be done to make it shine. The cost of replacing it is more than my husband is willing to spend. Thanks in advance - Roxanne, July 02, Reply

R1: A good acrylic floor finish will do the job - which can be purchased from any good janitorial place , Willard

Q 5341: We are building a "hearth" out of natural slate to place our free standing propane stove on. How do I bring out and maintain the natural wet look? Does the grout have to cure for any period of time before we can seal it? Darline, July 02, Reply
R1: Dear Darline: Consider the application of a good-quality stone color enhancer. Ciao and good luck, Maurizio, Expert Panelist
Q 5335: I am putting in a granite or slate kitchen counter top and granite bathroom tops in my new condo. Your site was very informative. I am also beginning to work with local contractors in their business to assist with material acquisition. Alice, July 02, Reply
R1: Dear Alice: And the question is … Ciao and good luck, Maurizio.
Q 5331: I have an area that will not grow grass well. It is an area shaped like a lope-sided tear drop. I have been thinking of putting down some stone. Slate has come to mind. However I am not interested in putting any mortar between the stones (whatever kind) I use. My question then is how to do this so that the stone will remain still and shift at a very minimum. With other stones there are instructions on how to handle the ground (till, put in sand, etc., etc.). Do I have an option here with slate? Please advise, July 02, Reply
Q 5330: We have a black slate fireplace mantel that looks more gray than black. Can we use a sealer to darken the color? If so, what sealer do you recommend? Thanks! Cherie, July 02, Reply
R1: Dear Cherie: A good quality stone-color enhancer should do the trick for you. Ciao and good luck, Maurizio, Expert Panelist
Q 5328: I am planning to have a slate patio installed. Our water is extremely hard with lots of calcium + other minerals. The water will surely leave unsightly deposits and staines within a few weeks. Is there a sealer that can prevent this? I read about Cabot offering a waterproofing sealer with Teflon. Does this make any sense? Richard, July 02, Reply

Q 5325: I am attempting to lay 12x12 black slate tile floor in my kitchen and am finding inconsistencies in advice from many experts...i am hoping you may assist me....
1. i currently have linoleum that is well adhered and had planned on laying 1/4 inch concrete board without removing the lino...is this ok?
2. i am certain that i want a satin finish, but there seems to be a discrepancy at what point to seal the slate...should i seal each piece individually before installation, seal after installation but before grouting, or after grouting???
3. what type of sealer would you recommend for a high traffic and possible spillage area??? shane, July 02, Reply

Q 5324: I recently installed 4x4 slate on a Hardibacker wall (with one inch air gap) behind a pot belly wood stove. My question is about gloss sealers. Is there a special product which can take the intense heat in a stove area? Is lacquer base better than water base? Tomy, July 02, Reply

Q 5314: I just had my bathroom remodeled with a natural "rainforest" slate (greenish with tan and brown fossil patterns, probably from India) on the floor, countertop and tub surround and backsplash. I want it to look the way it looks when I sponge water on it, but not shiny. I've been told to use "color enhancer" but need to know which product is best. Should it be "surface" or "penetrating", acrylic or urothane, does it need to be a sealer as well, and is there a difference between the high-priced brands and those that are more affordable? Deanna, July 01, Reply
R1: Dear Deanna: A color enhancer is a below surface (penetrating, that is) product; therefore it will darken the stone without altering the original surface finish. You can get my maintenance guidelines for residential stone installations by giving me a holler at: info@findstone.com. They do carry a small price tag, but are worth every single penny and then some! It’s a one-of-a-kind document that you won’t find anywhere else, I promise! What’s more, I will also tell you a way to get your money back!Ciao and good luck, Maurizio, Expert Panelist

Q 5309: My home is 60 plus years old. The fireplace hearth is made out of slate (I think). I have tried many different ways (wax, marble polish, etc.) to bring out some luster but I am getting no way. I don't want it shiny, I just don't want it as dull as it is. Any ideas. Thanks, Kimberly, July 01, Reply
R1: Dear Kimberly: Sure, I’ve got plenty of ideas! but the slate people don’t like them very much for some reason. See my answer to the post 5308 below. Ciao and good luck, Maurizio
Q 5307: I picked up a sample of 12 X 12 slate at Lowe's and I am considering it for a kitchen, laundry room and bathrooms. What are the advantages and disadvantages of slate? Is slate hard on the feet? I have difficulty telling which side is up/down. Also it appears that there are layers of slates in this material when viewed from the edges. Any advice you can give would be helpful. I plan to install myself after much study. I have installed tile but never slate. Sincerely, Fred , July 01, Reply
R1: Dear Fred: Let me start from the pros of slate flooring in a kitchen, laundry room and bathroom … hmmm … I must have a temporary loss of memory, because I can’t remember any. Ok, let’s get to the cons; I remember those! … Oh, I’m sorry, I can’t say them: the slate people would get upset, and we don’t want that to happen, do we?! :-) Ciao and good luck, Maurizio, Expert Panelist
Q 5303: I have a vermont slate foyer and the grout between the slates I would like to remove. I have already tried removing some of it with carbide bits attached to dremel tools and hand grout removal tools, and the process is very slow and tedious. The grout has a consistency like mortar, is that normal?If you know of a better and faster method to remove this grout I would appreciate knowing Also, how deep do I have to remove the grout to get a good bond with new grout? Thanks, Dennis, July 01, Reply
Q 5302: We are looking to install slate flooring . What bare the best tips for this procedure? The surface to be tiled is smooth concrete, with no cracks. What is the best
adhesive to use? Should we seal the tiles before doing the grouting na dthen again
afterwards? Jonathan, July 01, Reply
R1: Dear Jonathan: You don’t want to know what I think about slate floors; therefore I won’t make any comment. About your questions, I reckon that them slate people who don’t like me too much should try to find some time out of their busy selling schedules to answer them. It never happened before, but, like the saying goes, there’s always a first time for everything! Ciao and good luck, Maurizio, Expert Panelist
Q 5296: I would like to seal floor of bathroom and shower, made of black slate. I would like a semigloss appearance, Sandra, July 01, Reply

Q 5295: Split some red candle wax on my unsealed slate fireplace hearth. Having read through your comments to others, am I correct to conclude nailpolish remover or acetone may get the wax and stain out of the light grey slate. A poor attempt with scraping, then scouring it out only seemed to make the wax go deeper into the slate....haste makes waste. What should I do? betsy, July 01, Reply

Q 5294: Can you use Mastic to adhere slate to wall? I'm planning to cut slate into 4 X 12 rectangles and mounting on wall to use as "baseboard". Thanks, Mark, July 01, Reply

Q 5293: How do I clean crayon scribbling off of a slate fireplace ? Anthony, July 01, Reply

Q 5290: Hello, I have access to beautiful slightly used slate roof tiles. They are in various shades of gray. I was thinking about using them as my counter top material or possibly as floor tiles. Is this being done? What are some of the things I will need to be concerned about. We are a organic household and enjoy the possibility of using this renewable source. Thank you for any thoughtful feed back, Candus, July 01, Reply  

Q 5287: I have a 90+yr old house with a black slate sink. The sink is structurally sound but somewhat greying... I have noticed some people have some very black slate sinks. Is there a simple way to clean up or polish the sink, Dan, July 01, Reply

Q 5135: My husband and I are building a home and I have been trying to decide on a material for the kitchen countertop. At this point, I think I want to go with slate tile but I'm finding a wildly varying price range. There is one place online that sells "brazilian" slate in varying sizes for about $2.50 per sq ft.
1. Is all brazilian tile the same hardness and porosity?
2. If it is an inferior tile, can the porosity problem be fixed with a good sealant?
3. What is considered a minimum thickness for a kitchen tile?
Sorry for all the questions, but this is a big step for us and I want to be sure. A big slab of stone is way out of our budget, but I am also leery of a price that seems to good to be true. Sincerely, Judy,
June 3, Reply
R1: Judy: Let me explain you something: I'm a maintenance man, and I HAD to write postings against slate (especially in a kitchen!) on the account of all the complaints and gripes that end-users have with such a material. However, the slate merchants who use this wonderful site for their trade complained quite loudly with its management because my comments were hurting their business. I believe that what was hurting their business were the complaints themselves, not my comments, but I decided not to follow up any longer slate posts. At the same time I encouraged those merchants to take care of their own customers. I think it's only fair. The complaints kept coming in like clockwork, but never received one single follow up. They were too busy selling it, I reckon. I promised then that I wouldn't make any comments about slate anymore and I'm going to keep that promise, but I sincerely hope - also considering that you don't sound extremely wealthy - that you can draw your own conclusions. Ciao and good luck, Maurizio, Expert Panelist
Q 5154: Planning to use slate on the floor of my cabana, should I seal it and if so will it be slippery? Margie, June 3, Reply
R1: Hi Margie, Depends on the sealer-seal on tile and try it on site. If there is going to be a high level of moisture or water I would seal it with an impregnator rather than topical sealer. Topical sealers can give you a real headache in the future "Stone"
Q 5162: I just purchased 40 - 12"x12" inch sheets of 2"x2" slate to use for a kitchen backsplash. The Chinese slate is all covered with mud which hides the true color. I have spent over 1 hour trying to clean 1 sheet and am making little progress. I have used a wet sponge and scrub brush which is removing it slowly. I plan to use and enhancer and selant before installing. Any suggestions on removing the mud ? Thanks, Stern, June 11, Reply
R1: Dear Stern:You do NOT want to know what I think about your problem. I sure hope that the slate merchants will chime in! (Don't hold your breath, though…)Ciao and good luck, Maurizio, Expert Panelist
Q 5186: I recently purchased and installed a multi-classic slate. I sealed the slate with a penetrating sealer prior to grouting the floor. I am unable to restore the original appearance of the tile prior to grouting. I have tried a stone cleaner and also applied another coat of the penetrating sealer and am unable to remove the haze from the tile. I read a few previous questions/answers and I would like to verify with you what I have read: 1. a 50/50 soluton of muratic acid and water will remove the haze and NOT harm the tile? 2. a surface sealer will give the tile a "wet look" without a glossy look - you mentioned a product called Miton 42 that would work best - how/where can I purchase this product? Regards, Shawn, June 16, Reply

R1: Dear Shawn: Where are the slate people when you need them? Sorry, they are too busy selling the stuff! Ciao and good luck, Maurizio, Expert Panelist
Q 5193: We just put a natural black slate on our kitchen floor and i feel as though it is not clean i like the natural look but for my sanity i think we'll have to put something on it lots of kids and pets running around what should i do? thank you kim, June 16, Reply
R1: Probably a good top finish will help a lot. Try one tile and use it for a week, see how it performs. Stone
Q 5201: Just installed a new slate floor outdoors around our home pool and deck in South Florida--about half will be under roof. It is Indian slate. The colors run from blue-black to yellow mud. Some is very flaky. We like the way all that looks and picked the slate partly because it seems to be relatively non-slip. From reading the questions about slate, I wonder if there is a problem with it bleaching in the sun or deteriorating in other ways. Should we seal it? With what? We are satisfied with a natural dull look, but some sheen would be OK if it did not make it slippery. I have talked to one company that is recommending a two-part finish that they make. They say they will add non-slip and it will last 10 years. Two coats will cost about half the price of the slate, which seems high. but my big concern is that it will look like linoleum. If I wanted that, I would not have laid slate. Any suggestions will be welcome. John, June 16, Reply
R1: Dear John: Just sit tight and some slate people will chime in with all the answers! … I hope … You see the reason why you always read questions about slate is because the slate people, so far, never bother answering them. but … you don't want to give up your hopes! :-) Ciao and good luck, Maurizio, Expert Panelist
Q 5216: I have just had slate floors installed in a bathroom and sunroom in my house. The advice on sealing and how to seal is very spotty and conflicting. My contractor told me to wait several days to let the stone cure and then to sponge on a thin coat of sealer. The product instructions say I should let the floor cure for thirty days, wash it with acid wash and then apply sealer with a lambswool applicator. All of the websites I have read say that I should not use any kind of acid on stone floors. I am totally confused and I wanted to get it done today before company arrives tomorrow for the holiday weekend. This brings me to my last question. How long does the sealer need to dry? My contractor said for about 8 hours. No one else gives specific information. Just instructions to wait until the sealer is dry. -Dayna, June 17, Reply
R1: Dear Dayna: Just sit tight and some slate people will chime in with all the answers! … I hope … You see, the reason why you have all these conflicting opinions is because the slate people are too busy selling the stuff to bother assisting their own customers. but … you don't want to give up your hopes! :-) Ciao and good luck, Maurizio, Expert Panelist
Q 5241: I just bought some african multicolor autumn slate to use for my kitchen counters but I was trying to clean it before installing it and all the orange and red color keeps coming off-it seems no matter how many times I brush it (I am using a firm brush with water and laundry detergent) I continue getting a residue and the bright colors are becoming very dull and dark-is this normal or did i get a bad batch of slate-please help! thank you Pat, June 20, Reply
R1: Yes it is normal. Ciao Stone
R2: You need to apply a sealer to stop the color from coming off - the color will be enhanced and your tile protected with a gfood acrylic sealer.Willard
Q 5256: I'm building a patio deck on the back end of my house In Portland or of course it rains alot here. I'd like to accent the steps with and outdoor tile like Slate or Granite. How do I prepare the step surface I've done alot of ceramic tile and marble flooring inside but this is the first time for outside. Can I use a plywood base if si do I need the hard backer board and do I use a sanded grout to fill the spacing or is there something else I can use. Thanks, Don, June 20, Reply
R1: Hi Don, I prefer using cement boards followed with a membrane over it. Im not familiar here with the term hard backer board. I would also use epoxy joints to complete work. Follow the directions from your local glue supplier, thats the best way to have a good guarantee. Stone
Q 5260: I have multi-colored slate tiles to install in a new powder room. I want to select the ones with the most colors on them. How do I tell what they will look like when sealed? If I put water on them will that give me a resonable facsimile of what it will look like sealed? Thanks H, June 23, Reply
R1: Hi H, yes it will bUT, you should be presealing them, it makes it much easier to clean and you can actually see the colors before you lay them down. Choose an area larger than the actual floor to be done (ex. garage) lay them down in the same configuration as the washroom and apply a coat of appropriate sealer. As they are wet you will see all the colors vividly. All you have to do is move them around like a puzzle in the layout of choice. Turn them and mark them 1,2,3 , etc., (on the underside) That's it. Your installer can no longer make a mistake and you have the floor looking the way you like it. Ciao Stone
Q 5261: I was considering a slate countertop. Is this a good material to use and how does it compare to granite, soapstone or corian in cost? Thank you. Power, June 23, Reply
R1: Dear Power: It does NOT compare with any of the materials you listed. And you do NOT want to know what I think about slate kitchen countertops! (Actually, I'm sure you would, but the slate people would get pretty upset, and we don't want to do that, do we?!) Ciao and good luck, Maurizio, Expert Panelist
Q 5062: I am in the process of laying a rough JACK bLACK slate floor in India, and find that the material has arrived with scratches from the quarry - as a result of the transport, and abrasion of one tile against the other. Can these scratches be removed - would a coating on the stone help remove these scratches... they are not very deep but do mar the visual quality of the surface. I do not mind a darkening of the slate with a coating. Could you recommend an appropriate sealant. thanks Anjani , May 29, Reply
R1: Dear Anjani: I have not the faintest idea! (Or maybe I do …) At any rate, slate manufacturers do read these postings all the time. (In fact they got very upset when I was making not so flattering comments about slate in general!) Unfortunately, they are so busy selling their stuff that they have no time to help any of their customers out! but I am sure that in your case they will make an exception and solve your problem in a jffy! Maurizio, Expert Panelist
Q 5031: We have a builders grade slate fireplace surround and hearth in black. it always looks chalky. could you recommend a cleaning method and solution to seal the slate to bring out a richer color. John, May 02, Reply
R1: Dear John:Yes, you could apply a good-quality stone color enhancer. If you want to know more, gimme a holler. Maurizio
Q 5024: We are planning to move an older billiard table from one home to another home, a distance of about 10 miles. We plan to rent a 14-foot U-Haul truck. The slate, which is 3/4 to an inch thick, is ONE PIECE of approximately 4 feet wide by 8 feet long (we are not sure but guess that it weighs about 800 pounds). What are the recommended ways to truck this piece of slate without cracking it or damaging it? We have asked numerous movers and billiard table personnel this question and have received a lot of conflicting answers, including 'lay if flat on the truck bed', 'lay it flat on pallets', 'lay it flat on blankets', 'do not lay if flat', 'use an A-Frame', 'truck it on edge'. etc. So we think we need a conclusive answer from any expert. Zoppettie, May 02, Reply
R1: Zoppettie, The A-frame is your best bet for shipping the stone without damage. I try to ship anything under 3 inches thick upright. Thin stone should be moved around much the same as a sheet of glass. Good luck, JVC, Expert Panelist
Q 5079: I work in a wholesale brick & tile company in Nebraska. We sell some tumbled marble, travertine, slate, granite, and limestone. Can you tell me the differences between the tumbled marble, travertine and limestone. Also, honed, filled and polished marble, etc. This is very confusing to me when trying to explain to a customer. Also, I know it depends on where it comes from. I am just looking for a general description of how it is formed from the earth and by man when sold. Thank you for any help you can offer. Julie, May 29, Reply
R1: See the Library of Articles in this site itself
Q 5450: We have a small black slate floor in the foyer of our home. We have light white scratches in the floor from the kids playing with their toys. Should I use baby oil to take away the scratches or should baby oil not be used for floor? Chris
Q 5449: Will a sealant help prohibit iron from weeping through the surface of green slate? Jim,
Q 4661:I am buying a new home, actually an old home. Gutting the kitchen. I’ve always loved carrera marble but know that its awful for kitchen counters due to stains etc. So I’ve moved off that and am now very fond of French blue limestone...however you state that limestone is equally as awful for countertops...so here’s my dilemma. I want real stone—not Caesarstone or Silestone—and I absolutely disliked granite. So what are my options? Travertine? Slate? Soapstone? Any thoughts/advice would be greatly appreciated. Andrea, april 9, Reply
R1: We instal 5 kitchen per week of brazilian slate tops - it is very good product for kitchens - bathrooms etc.Willard
Q 4631: We just bought and installed a cast iron fireplace with a black slate hearth. It came with a smooth flat finish, all matt black, but no polish. While doing the decorating, some patches of stong wallpaper paste got onto the hearth, and some small spots of danish oil which had been used to repolish a coffee table.I can't seem to shift these substances, no matter what i try. I triepntd turps substitute (white spirit?), then a soft finish remover which is similar to white spirit, then what I believed to be an acetone liquid sold for removing sticky gluey things. Nothing moved the paste or spot of oil.I don't know what to do next. I'd be very grateful for your help and advice. Is it possible to use harsher things, or to use wire wool or a scouring pad for instance? I do not want to damage the hearth stone.We have another similar black slate hearth, and that one came polished. Can you give me any advice on polishing the unfinished one.Thanks in advance. Tricia, april 9, Reply
Q 4610: We just moved into a house 2 months ago with a screened in porch. It looks like it has a slate floor. However, it looks like the "slate", which is wet, is turning to mud! HELP. What is this and how do we care for it? Fran, March 29, Reply
Q 4600: I am installing multi color slate floors in my kitchen and family room. Should I seal with and enhancer or sealer or both? Does this seal the grout also, or do I have to use a different product? Please advise, March 29, Reply
Q 4524: We are purchasing a home with a fireplace. The previous owners painted over the slate type stones surrounding the fireplace with latex paint and possibly a primer. We want to remove the paint and bring the stone back to it's original state. Any ideas/suggestions would be greatly appreciated. Thanks Gayle, March 27, Reply
Q 4523: I am about to renovate the kitchen of my 1915 Victorian. I am trying to keep the appearance appropriate to the age of the house. Therefore polished granite is not the look I am striving for. I am interested in a countertop that provides a dark, dull, solid appearance, without the speckles typical of granite. I am interested in Pietra Cardoso, soapstone, slate, black-honed granite and any other product that fits this description. I would like to know how each of these stones reacts to spills, such as wines and oils and scratches. I am also interested in the maintenance requirements of each. I don't mind having to do monthly treatment, but don't want to have to do anything other than a wipe down each day. I also don't mind a stone that will take on a worn look with age but I want to avoid obvious staining. Also, is there a way to prep a stone when it is installed in order to prevent scratches and permanent staining? Jocelyn, March 26, Reply
R1: We sell 5 kitchen a week in slate counter tops in both honed surface and natural cleft - brazilian slate in almost impregnablke to spills once treated with mineral oil a monthly or bi-weekly treament - should a serious stain occur it is simply remover with 1200 grid emery paper - I have it in my house and would have nothing else - both from a maintenance point of view and mostly from an eye pleasing perspective.Willard
Q 4522: A small piece of slate (about six inches long, three inches wide) chipped off a slate porch. Can I glue it back on with epoxy or some other glue? Thanks. Eric, March 26, Reply
Q 4521: I would like to know more about the charactoristics of natural stones. Specifically granite, limestone, sandstone, marble, slate and flint. Thank you, Margaret, March 26, Reply
Q 4520: I am a contractor. I get many calls for natural stones applications and installation for marble, granite slabs and tiles, tumbled stones and slate. I would like info on installation tips and techniques. Thank you, Dustin, March 26, Reply
Q 4501: My daughter wants to put "Jet Mist" honed granite on her countertop - can you guide me re maintenance and if this is a good choice - She wanted a slate-look. She has a large family (5 children) and would appreciate any advice you may give. Thanks. Alicia, Feb 14, Reply
Q 4495: I recently bought tiles labelled "slate" at a building superstore to put on the floor of a new mudroom. They were inexpensive and rough looking, which seemed reasonable for an entry that sees hard use. I was not looking for a high end kind of surface. The sample tiles looked beautiful, with mottled soft gray and rusty brown surface. They were labelled made in China. THe installer has cemented them down, and I was surprised to see that the colouring on most of the pieces were much darker gray and very deep rust. Jan 9, Reply
Q 4491: Does anyone know how i can use the thick slurry in the quarries at Portland here in England to fire it ? Apparantly it just needs some chemicals added, any clues ? Greetings Sharon, Jan 9, Reply
Q 4419: I do not now who this MAURIZIO guy is that is giving all this advice but he should get alittle more info on stuff he speaks about. All slate is not the same we quarry vermont slate and all the stuff he speaks about slate does not include Vermont slate It works great in Kitchens, bathrooms, and it can br sealed with natural oils corn vere, ect. and when all these people are ttalking about discoloration on their floors thats from the wrong type of cleaners being used, the brown discoloration can be removed, After reading some of his stuff If I was lookingto purchase slate he sure would turn me off. So why not tell that all slates are not the same. STEPHEN, Jan5 Reply
Q 4109: I have been having a very difficult time cleaning my slates floors. Everyone tells me to do a different thing to do. What should I do? I have black slate in my shower and on the floors. In the past I used Miracle sealer and Miracle enhancer. My floors and shower have white marks coming out. It looks very dirty. Please help! Dana, Nov2. Reply
R1: Dear Dana: For your mental well being, rip it out and start all over with a more proper stone. Maurizio
R2: Dana, Please do not rip it out. It is Perfect. You just have calcium deposits. LimeAway and elbow grease will take it off. Once you have that done then re-seal the shower with an acrylic solvent based sealer. This will protect the surface of the stone. Do this Once a year and you should have No troubles. best Regards, Stephen, Slate Expert - Canada
Q 4121: I have scratched some slate tile on my floor with a piece of machinery and do not know how to treat this scratch. It is fairly deep, about 1/8", and fairly long and wide. I would rather not replace the tile, so do you have any suggestions about repairing this scratch? I saw your article about contacting you concerning the correct tools to perform this operation. I hope you can elaborate, bob, Nov2. Reply
R1: Dear bob: Nobody can remove a scratch. It would be like trying to remove a hole out of doughnut! What you should do is to eat the doughnut and the hole is gone! Same thing with your slate: you'd have to grind your tile along the scratch down to the depth of it, and the scratch is gone. The only unsurmontable problem is that you can't grind natural-cleft finished stone. This is by far the major draw-back with natural-cleft slate used as a flooring material: it can't be refinished. Forget it, replace the tile. Ciao and good luck, Maurizio, Expert Panelist
R2: bob, just wet the surface and stand back and see if it kind of disappears. If it does just dab a bit of acrylic sealer on it. If it doesn't work then try to match a grout color to the slate and fill the trench in with some grout. Then seal the grout. best Regards, Stephen, Slate Expert, Canada.
Q 4200: I'm planning on installing clefted slate on a bathroom floor. Is it ok to use Aldon's Grout Easy to prevent grout build up on the slate? Also should I use a sealer? Water based or solvent? Lyssa, Nov15. Reply
R1: Lyssa, I do not know anything about Aldons Grout Easy. The best looking Slate floor that I have seen is a floor that was installed and grouted then 10 days later we sealed it with an acrylic solvent based sealer. A clean bucket of water and good sponges will do the job. Do not waste your money on high priced products. best Regards, Stephen, Slate Expert, Canada
Q 4112: Our home was built in 1980 and has a slate foyer. Not to our surprise, the underlayment used was not sufficient and the floor is now quite loose. What do we need to do to repair the loose tiles and what type of grout and sealant do you advise we use to protect the flooring? Also, how long does it take for the repairs take to hold? Liz, Nov2. Reply
R1: Liz, Try to remove the tiles and not break them. Then try to remove the thinset underneath. Then just re-install the tiles and grout them and re-seal the surface with an acrylic solvent based sealer. best Regards, Stephen, Slate Expert, Canada.
Q 4125: We built a new home with slate surrounding the fireplace and on the hearth.
I believe it is an Indian slate ("beach sand" color), which has not been honed. The color is very light and we want to darken it quite a bit to bring out the natural colors and depth. I tested two products by Aqua Mix on some leftover pieces -- "Stone Enhancer" (water based formula) and "Low Sheen Sealer". They both barely hardly darkened the slate at all. We want it much richer and darker, with minimal sheen. What product should we use?
No products have been applied the the slate so far. Thanks. brenda brend
a, Nov5. Reply
R1: Dear brenda: None. Get a darker slate. Maurizio
R2: brenda, Maurizizo do not know what he is talking about. He is prone to Marble and not slate. It is like asking a Santa Claus how he delivers his Easter Eggs. O.K. beach Sand is a color that we sell in North America. There is a Product that makes it wet looking called Miton 42. Try to wet it and see if you like the darkness. Look up Miton 42 on the Internet and you should find us. We sell it. It will do exactly do what you want. best Regards, Stephen, Slate Expert, Canada
Q 4140:   My friend has black slate in her entryway. She was thinking of covering it with another flooring product. I was wondering if she can lighten or change the color by using some sort of acidic liquid. The slate is about 30 years old, and has not been sealed in probably 30 years, so it is quite pourous. It appears to be sawn slate, it is very flat, symmetrical squares, Nancy, Nov6. Reply
R1: Dear Nancy: No, black slate is not porous at all. That's why they use it as roofing material. Tell your friend to go with her original idea to have a new floor installed (not slate, I hope!). Maurizio
R2: Nancy, re-install a new slate floor. You will love the feel of the imported slates. The material that you have is from Quebec. but no you will not change the color by adding acid or other topical substances. best Regards, Stephen, Slate Expert, Canada
Q 4182: What's your opinion about slate as a countertop material. Does it need to be sealed? Are the minor scratches a problem. bottom line: Is it tought enought for a high traffic kitchen with 3 kids and lots of cooking? Lisa.J, Nov14. Reply
R1: Dear Lisa; No, it does not need to be sealed. It needs to be totally forgotten about, and big time, too!! You do NOT want any slate it in your kitchen! Maurizio
R2: Lisa, We are installing about 10 Kitchens a day with brazillian slate for countertops. We seal ours with Mineral oil once or twice a month. It will handle the kids. Mineral oil takes the scratches and makes them disappear. Slate is Great. best Regards, Stephen, Slate Expert, Canada
Q 4224: I am at the grouting stage, and I was told by the slate company that the impregnator sealant will seal that grout as well as the slate. What I am wondering is, do I still have to wet mop the grout 2x a day for three days before I seal the floor or can I seal 24 hours after grouting and leave it at that. (I already have one layer of impregnator on.) Thanks. Shari, Nov20. Reply
R1: Dear Shari: Well, for starters, your fisrt layer of impregnator shoud be IN, not ON. Second you want to leave the grout cure for a few days before you seal it. Maurizio
R2: Shari, Maurizio finally has something good to say, for once. You should of let the grout cure for at least 7-10 days. but you do not need to mop the floor that much. best Regards, Stephen, Slate Expert Canada
Q 4229: I have a vermont slate entry foyer. It is down with mastic on the 3/4" decking of the house can I ruff the surface and install tile over it? Nov21. Reply
R1: You can and we have do it but I will not recommend it. It do not take long to rip out the old slate and put in new slate. best Regards, Stephen, Slate Expert, Canada
Q 4234: I am about to lay a brasil Verde slate floor with tiles of 30x30cm to be finished with a matt sealant. Can you suggest a colour for the grouting? Also what distance would you recommend between the tiles? Thanks Amanda, Nov21. Reply
R1: Amanda, You can use a green colored grout but I would use just Natural Grey grout. and the grout lines be about 1/4" wide. best Regards, Stephen, Slate Expert, Canada
Q 4235: My spouse and I just installed an African Slate flooring, it's beautiful, but do we need to do anything else? (ie seal it?). Lydia, Nov21. Reply
R1: Yes, Lydia, you should seal it. If you like it when you wet the surface the use an acrylic solvent based sealer. It will pull out the colors. best Regards, Stephen , Slate Expert, Canada
Q 3069: Firesurround, in old painted slate, not sealed colour uneven, can see black in patches allover, how do i restore?, any advice would be helpful. thankyou, Clare, Oct 21. Reply
:R1: Clare, you need to get a stripper and stirp the surface back down to the raw surface and let dry. Then re-seal the slate and away you go. best Regards, Stephen, Slate Expert, Canada
Q 3093: How do you get white bleach spots off of a non-sealed black slate table top? The bleach bottle left huge white spots where it was sitting? Doesnt wash off. My boss is very upset, Vince, Oct 23. Reply
R1: Dear Vince: Well, the only good thing in this picture is that it happened to your boss
and not to you! The only way to "remove" bleach marks is to do the same thing that you do when fabric is bleached, which is: NOTHING! Anyway, if the table top was ground and honed having it re-ground and re-honed by a professional stone refinisher will do the trick. If it's a natural cleft finish, then it's terminal. And, by the way, sealing it with a stone impregnator will hardly do anything even for the future. Maurizio
R2: Vince if you wet the white surface, does it disappear. If so put a coat of acrylic sealer over top . First try to pour pure Muratic acid on it and scrub with gloves on and then rinse it off. Then seal it. best Regards, Stephen, Slate Expert, Canada
Q 3096: I bought a pool table from a friend of mine and i was wondering if there is a secret to filling in the screw holes with wax, filling the seams with wax (three piece slate), and putting the felt back on. if I could get some instruction on these matters it would be much appreciated. Thanks.Tim, Oct 23. Reply
Q 3047: email me relevant information on tiling my fireplace with slate. I've already tiled it. My concern is wether or not I should apply a sealer prior to grouting. If so which would be best to use for slate. Thank You, brady, Oct 19. Reply
R1: Dear brady: What do you plan to spill on your slate that you feel like you need to seal it?! If you're thinking about a topical sealler (Urethane or such), then you want to apply that a few days after grouting.Maurizio
R2: Put a coat of Acrylic sealer on it and that will make it look nice. best Regards, Stephen, Slate Expert, Canada
Q 4042:   I have what I believe is a slate floor in the entry of my home which was built in 1967. based on the condition of other parts of the house, I don't think it has been cared for properly. What is the proper care for a slate floor? Is there any way to "lighten up" or enhance the color of the floor? Thanks, Joan, Oct 24. Reply
R1: Dear Joan: Rip it out. You'll be glad you did! Maurizio
Q 4023: we are in the process of looking at slate for a shower. The slate is from China and the various colors are gorgeous. We would like some advice about using Color Enhancer to bring out the natural color and than using a sealer to help reduce some of the problems that may result from using slate in a shower. Is it advisable to use a color enhancer first, let it cure and then go with a sealer? Charity, Oct 24. Reply
R1: Dear Charity: Yes, that's what you have to do. Maurizio
Q 4022: My son recently purchased a coffee table with a hexagonal slate top. The slate is a dark charcoal gray, is very rough-surfaced and is sealed. There are some round light gray stains and a few scratches in the slate. What is the best was to return the top to a uniform color. He has tried to clean it with tri-sodium phosphate and other "home made" cleaners, with no avail. Do we need to strip the top and reseal? Ed, Oct 24. Reply
Q 3057: I have cleft copper slate from India in a foyer. It was installed seven years ago and finished with Sparks Stone Glamor. The slate still looks good but i was wondering what should be used for general cleaning and whether it would be advisable to apply more of the finish after a good cleaning. basically nothing has been used on the stone except damp mopping and vaccuuming from day one. Thanks for any input. Jim, Oct 20. Reply
R1: Dear Jim: I don't know this "Sparks Stone Glamour" product. Is it a strippable topical finish, or a permanent one (Urethane-based or something)? Without that piece of information I can't give you any advice. Maurizio
Q 3059: We have just had a new slate floor installed in our basement. After 1 week, we applied 2 coats of sealer to slate & grout (Miton 42 - acrylic solvent sealer) as instructed by the installer. About a week after the sealer, my husband was cleaning up some construction dust, etc. and mopped some of the new floor with a mop that contained much soap (from a previous clean up of the old cement basement floor) DUHH! Now the some of the grout on the slate floor has white residue in the "mopped" areas (presumably it is soap?). I have cleaned the grout multiple times with water and it seems to be helping a bit, but whenever it dries, the white appears again. What I'm wondering is if
we could apply more sealer over these areas (would it get rid of the "whiteness") or do I just keep cleaning with water until it is all removed. HELP! Jerry, Oct 20. Reply
Q 4059: Thanks for what seems to be an unusually brilliant resource. However, I can only find repair and restoring advice as opposed to information on how toget things right in the first place.I've just laid a slate floor in my kitchen. I haven't even grouted it yet. What should I do? Thanks, Per, Oct 24. Reply
R1: Dear Per: Oh, you're wrong about that! Personally I give more advice about selecting the right stone for the right place (when I have a chance, of course!), than maintenance tips after the cutting of the ribbon (see my answer to the posting 4058 right below yours!) So, I really don't know what and how extensively you read this place, but if you had read it deep enough you would have found out that always tell people to stay away from slate in the kitchen. Now, please, don't ask me what you have to do to make it enjoyable. If I -- or anybody else for that matter -- had an answer to that, I wouldn't be telling people not to use slate, would I! Get rid of it. It's only money! You have an option, though: you can always ask the merchants who sold the slate to you how to make it enjoyable! I'm sure they know everything about it and then some!! Maurizio
A 4058: Water-tight with that stone? Not in your lifetime! Yes, keep sealing it, and sealing it, and sealing it ... It's going to be any day now before it's sealed ... Any day ... "Now, remember, when it comes to natural stone, maintenance is an all too important yet neglected subject that should begin before you even select it, as you can tell from several of this very site's postings! Don't become another statistic! Maurizio
R2: Per, Can you elaborate on what information you are interested in? Regards Steven, Expert Panelist
R3: Dear Per, If you like it just enjoy it. Slate has it's problems but so do many other materials, marble being just one example. A good piece of Welsh slate as I have seen, will last hundreds of years on a kitchen floor and look even better for it. bryan UK
Q 4081: My wife and I are considering purchasing some black slate type counter tops, that have been taken out of an old school. Can you give us any advice as to what quality of slate that this probably is and do we need to apply any sealant, after installation. Also, how easy will this be to have cut? Thanks for any advice you may be able to give us, as we have little knowledge of the pros and cons of slate in use as a counter top. Thanks, Lonnie, Oct 29. Reply
R1: Dear Lonnie: You do NOT want to do that! Maurizio
R2: Dear Lonnie, briefly the cons, it scratches very easy and some say it's bland. The pros, for others nothing matches the look of a well honed slate, it is impervious to water and is resistant to most chemical attack it also cuts easily. As for treatments, either none take a chance on one of the many commercial treatments or if you can out up with the smell for a few day's boiled linseed oil was traditionally used in my area. If it was used for blackboards it's usually tops. Good Luck bryan UK
Q 4063: Hi – I found some 4” slate tiles that I would like to use for a small bathroom countertop. Is slate a good choice for bathrooms? If not, do you have any suggestions of a material that has the same look as dull slate? Thanks a million! TARA, Oct 24. Reply
R1: Dear Tara: No. No. Maurizio
R2: Yes slate is good for a bathroom countertop. If you want to keep the dull look then just seal the slate with a penetrating sealer. I like kind of a wet look and you can achieve that with a surface coating sealer. This will also make the water bead for easy clean-up. Research your sealers first in your local area. Do not use Tile-Lab. best Regards, Stephen, Canada, Expert Panelist
Q 4071: Hi! my slate countertops in our kitchen have become scuffed and scratched. I do not believe they were sealed when installed. How do I remove the scratches? Is there a rubbing compound that is safe? Jim, Oct 29. Reply

R1: Dear Jim: Nope. Now, listen very carefully to me: get rid of your slate countertop as fast as you can. It may hurt your wallet, but remember, it's only money! Your mental health should come fisrt! Maurizio

R2: Please do not listen to Maurizio on this one. Your slate countertop is fine. Just go to the local Pharmacy and pick up a bottle of mineral oil. Try a test area first on you countertop to see if the oil gets absorbed and makes the scratches disappear. You only have to do this once or twice a month. That is it. Please do not rip out the slate. The mineral oil should help your troubles. Once you have enough oil in your slate then you can try the scratch test. Just take a sharp object and lightly run it across the surface about an inch or two. Then just rub the scratch with your finger and magic it is gone. best Regards, Stephen, Canada, Expert Panelist
Q 4078: I am in the process of remodeling my kitchen/family room. I have chosen "imperial red" granite for the countertops and a multicolor slate for the floor. Are these good choices as far as performance and durability? Easy care? Any advice is appreciated because there is still time to make changes if I act soon. Great site! Thanks, Renee' from Fort Worth, Texas, Oct 29. Reply
R1: Dear Renee: "Imperial Red" is good. Slate for the floor is not. Now, remember, when it comes to natural stone, maintenance is an all too important yet neglected subject that should begin before you even select it, as you can tell from several of this very site's postings! Don't become another statistic! Maurizio
R2: Yes you have chosen the right products. You will like your slate floor and the granite countertop. One piece of advice is please do not use Windex on the counter. Maintaince on the slate floor is very low. If you like the wet look then seal it with a surface coating sealer and just maintain the sealer once every one to two years if you like. Just listen to me on this one. best Regards, Stephen, Canada, Expert Panelist
Q 2885: We have a bit of a problem... My school has a wonderful brass compass embedded in the floor tiles of the main entrance hall. We were able to clean the brass compass with vinegar. We noticed the surrounding slate tiles are now lighter. They were gray, blue and some deep red. The red slate seems about the same color, the gray and blue and very light now. They had 60+ years of build up, and we thought the old wax was coming off. What do you think, and what should we do to make them all look alike again? Thanks for you time, Eager in the East, Oct 8, Reply
R1: Dear Eager in the East: First, you try to strip all the lod build-up of the wax, and see how the slate looks like. If the venegar only damaged the wax, then you're in good shape. If the vinegar found its way through the wax and damaged the slate, then you're out of luck. You may want to consider the services of a local stone refinishing contractor, but I doubt that they'll be able to do something for you. Maurizio
R2: Eager, all you have to do is just a little bit of work and you can do this yourself. First, strip the sealer and get right down to the slate. Then give the slate a bath in muratic acid 50% and water. Then reseal the floor in a surface coating sealer and no more than three coats. Use a paint pad to apply an even coat. then just find a floor wax and maintain the sealer with that. We use a wax called Plaza plus. best Regards, Stephen, Canada, Expert Panelist
Q 2886: I hope you can help us. We own an 1856 home with slate fireplaces that have been painted white! We have used a paint remover to remove the white paint and of course, realize that these mantles were probably faux painted with black paint to look like marble...We see some indication that this is the case. The slate is a beautiful green/black color. Now, however, we need to know how to make (and keep) our mantles looking their best once the paint is completely removed. Some have suggested mineral oil with a small amount of black or dark black/green paint. Could you tell us if you agree with this suggestion? Many thanks...Dian, Oct 8, Reply
Q 2887: Hello. What a great site! I live in south Mississippi and am looking for 12"x12" or 16"x16" slate pavers (Jade green or natural grey guaged one side or two). Also, do you recommend any sealant on pavers used outdoors (if so, which one/type) or is it preferable to allow them to weather naturally? David, Oct 8, Reply
R1: Strip all the paint off first. Once you have that done just get a surface coating sealer and that will make it look beautiful for the rest of you life. best Regards, Stephen, Canada, Expert Panelist
Q 2906: We have a textured slate floor that receives heavy traffic every day. It is light in color but gets a thin black film of oil and grease that does not completely clean even after daily scrubbing. The only places that appear very clean are where the rubber tires of the floor scrubber spin. We are curious if there are any rubber nubbed brushes available for Noble floor scrubbers or Clark scrubbers. We have tried many types of degreaser products but none seem to do the trick. Thank you. Doug, Oct 8, Reply
R1: 50-50 water and vinegar soak; scrub, rinse , problem gone. Tony
R2: Try striping the floor. Remember that the sealer is stained with the grease Not the slate. Strip off the sealer and reseal the slate floor with no more than three coats of a surface coating sealer. After about a year if may look dull then find a floor finish or wax to maintain the sealer which will put a hard surface on the floor. Then Remember do not use Hot Water. The sealer will come off. cold water is better. best Regards, Stephen, Canada, Expert Panelist
Q 2909: I have been in the Floor covering trade for more than 30 years now, having close contacts with the main Architects / Designers / Hoteliers / Specifiers in India. I intend branching out into the natural Stone trade, for which I know a substantial demand exists. I would be thankful if you could furnish me with some basic start-up knowledge / info as to what all is involved in the natural Stone / Slate line and all that I need to know about  this. Many thanks, Puneet, Oct 8, Reply
R1: I would strongly suggest finding out some other line of work or stay where you are too. Everyone now is bringing in slate and selling it. It is even hard for the big guys to sell slate now let alone someone new. It will take about five years to maybe see a profit. best Regards, Stephen, Canada, Expert Panelist
Q 2912: I have a slate water fountain - which has turned colors during my move - I love the relaxing sound but currently hate the discoloration - If you could point me in the right direction or give me some pointers I would be grateful. Christina, Oct 8, Reply
R1: You must have one of those Chinese little water fountains. I have the pebble one. Calcium I think is your problem. It loves slate. Try Limeaway or CLR. best Regards, Stephen brazil ,Canada, Expert Panelist
Q 3039: What is the best sealant for outdoor colored slate tiles from Vermont? I live in the Northeast where the winters can be harsh. Thank You, Nick, Oct 18. Reply
R1: The best sealer if it is out doors is a surface coating sealer. There are lots on the market. You need something like a concrete sealer. This will make it wet looking and protect your slate from the harsh weather. best Regards, Stephen, Canada, Expert Panelist
Q 2927: we have just acquired a painted slate fireplace, circa late 19th century - mantle and vertical pieces - it needs a clean and I wondered if you could tell me the best way to do this without removing any of the paint as we like the colours. many thanks, Vicki, Oct 10, Reply
R1: Oh! The slate will look better but if you like then go ahead. Use luke warn water and lightly scrub the surface. Maybe that will work. Someone else may tell you the right way. Or visit a paint store and ask them. best Regards, Stephen, Canada, Expert Panelist
Q 2930: Our 1820's farmhouse includes a slate fireplace (oringinally used for coal) in the dining room and 10 x 10 marble floor in the vestibule at the front door. The slate is currently covered with mutliple layers of paint. Any suggestions on the proper way to remove the paint? Any helpful hints on how to bring out the natural look? What should we stay away from using? On the vestibule, I will hire a contractor to refinish the floor, but should the grout be applied before or after the floor is refinshed? Thanks. Mike, boston. Oct 10, Reply
R1: Strip off the layers of paint and you will see the beauty of slate. Yes you should grout the floor first because it holds the floor together. best Regards, Stephen, Canada, Expert Panelist
Q 2947: First, this is an awesome site, wish I had found it bEFORE I listened to the folks at Home Depot! I’m in the middle of a project where I am putting slate on top of a cement porch. I have used sanded grout and it is ALL OVER the slate. I was told that I could “simply wipe the grout off” after waiting for ~20 minutes. This was DEFINITELY NOT the case! (and no, I didn’t seal the slate first) What can I use to get the grout off of the slate? In most places, the Slate has a haze. In addition, once I get the haze and excess grout off, what should I do for maintenance of the slate? Thanks, Denny, Oct 10, Reply
R1: Dear Denny: I really don't know. To clean grout residue the way you describe it, tile people use some sort of acid cleaner, but most slate don't agree with acids and get badly damaged by them. I'd suggest you to go back to the place where you bought the slate. They've got your money, they should be able to help. Maurizio, USA
R2: Denny, Strip off the sealer and bath the slate in Muratic acid to get the haze of grout off. If you have big amount of grout the use a knife. For the hard to get ones use a steel brush. Then reseal it with a surface coating sealer. Oh! and one more thing. Do no buy your slate anymore from a person hired for $5.00 an hour. or Home Depot. They are ruining the slate market with their junk stones from the quarries and low prices. It makes us guys look bad and the slate industry. best Regards, Stephen, Canada, Expert panelist
Q 2952: We have a cleft slate floor that was recently installed in the entry way of our home. We are looking for and effective sealant...and have been told that mineral or baby oil would suffice as a sealant. Is this true and what are the advantages or disadvantages of this method as compared to other sealants. We would appreciatre any suggestions or recommendations. Thank you, Clay, Oct 10, Reply  
R1: Dear Clay: First, what kind of staining agensts you're envisioning to spill on your floor to consider a sealing job? Second, if it's domestic (from New England) or Italian slate, it does not need to be sealed (it won't take any sealer in). Third, baby oil (which is mineral oil with some fragrance) will evaporate and seal nothing. It will only temporarily darken the stone. An impregnator/sealer for stone will permanently seal the stone (if it can take any of it in) without altering its original color (with a few exceptions). If you want to darken your stone in a permanent way, then a good-quality stone color enhancer is "your man". Maurizio, USA
R2: PLEASE do not use mineral oil on the floor as a sealer. Only on a countertop. Just imagine you sealed you floor with the mineral oil and someone walks in over it and onto the carpet and up the hardwood stairs. bad Idea. Just use a surface coating sealer and let dry over night. apply about two coats and that should take care of any of your worries. best Regards, Stephen, Canada, Expert Panelist
Q 2954: We are currently trying to attempt to lay slate on our stair way inside our home. We have a split entry home and the landing is already slate so we would like to continue it on the stairs also. Currently there is plywood on the surface which comes in contact with oak end caps where the railings are. So we will be placing the slate on the plywood and our thought was to have oak molding to cover where the slate meets from the risers to the treads to cover the rough edges. Any tricks of the trade before we begin? We have never done this before and would like to try doing the installation. Please Help?, Nrpelet, Oct 10, Reply
R1: If you want just use a belt sander and take off the rough edge. Then just fit the tiles where you want them to go. best Regards, Stephen, Canada, Expert Panelist
Q 2957: We have just installed slate tile on our patio in Arizona, should some kind of sealer be applied. We plan to use it as a eating area., Salzach, Oct 10, Reply
R1: Dear Salzach: My answer to the posting 2952 below will fit your bill, too. Maurizio, USA
R2: We instal 5 kitchen a week in slate counertops - we recommend a wipe down of mineral oil on a monthly or bi-weekly basis Willard
Q 2975: First, I have a new brazilian Multicolor slate tile floor in my kitchen, and I want to know what to seal it with, if I should seal it at all. Also, when the tile is grouted, if there is any haze on it, my local tile shop has recommended that I remove that haze with a citrus-based haze remover formulated for natural stone. They also recommend that I follow this haze-removal process by rinsing the tiles with water. I understand from other entries that a citrus-based cleaner could damage the tiles. If that's the case, I am curious about what type of damage could occur.

Second, against the arguments of some of the experts who post answers on this site, I have a black honed slate slab countertop, also new, in the kitchen. (I read about the opinions of the experts on this site AFTER having purchased and installed the countertop.) I am not concerned about scratches or imperfections that will invariably appear in the stone over time, and I would rather not seal the stone. I would instead prefer to use linseed oil or baby oil periodically to enhance the stone's patina. Is this the best route, or should I use a topical or impregnating sealer? If I do seal or impregnate, may I then use baby oil periodically as an additional measure?

Finally, and also regarding the countertop, I am under the impression that I could wipe it down as a daily cleaning process using a slightly damp rag. I assume that process would not cause the type of etching described on this site. Am I correct in this assumption? If not, what can I use on a daily basis for upkeep on this surface? Thank you very much for your help. Dana, Oct 10, Reply

R1: 34 years personal experience in the installation and service of natural marble granite and other stone products. 1.impregnate for lasting durability. 2.clean only with a solution of one cup of vinegar to one gallon of water period,this will remove any and all kitchen residues found in the average home with absolutely no harmful what-so-ever feel free to pick my brain on a vast knowledge on this subject. Tony
This is a comment to Tony's answer: 34 years of "experience" on the stone maintenance business and you still recommend water and vinegar!! ... I made so much money as a stone restoration contractor by fixing the damages made to polished marble by water and vinegar that I used to say that I was selling vinegar by the square foot, not by the gallon!! Fortunately, over the years, slowly but surely, most of the "geniuses" who used to recommend that, realized how ignorant and stupid they were. A few law suits here and there help them to understand that they should keep their mouth shut, too. but after 34 years you're still at that point! ... WOW, you're amazing, man!! If you ask me, there ought to be a law to put self-proclaimed "experts" like yourself in jail and have the keys thrown away! This is a site for experts, pal. You don't belong here. Get permanently lost. Nobody will miss you and your "vast knowledge" on the subject, I promise you. Ciao, Maurizio, USA

R2: Dear Dana: I don't know about this citrus-based product, but if at the store tell you that's formulated for stone, then it should be all right (I guess!). The brazilian multicor slate does need to be sealed real bad! Don't use linseed oil (too messy and smelly). Unscented baby oil (mineral oil) is your best bet. black slate won't take any impregnator sealer in. All in all, I feel deeply and sincerely sorry for the choices of stone you made for your kitchen. What to clean them with on a daily basis is the least of your concerns. Maurizio
R3: Dear Dana, Hmm, well lets see, Don't worry about sealing the black slate as the damage won't be from absorption. If you must wipe it down with oil use mineral oil. It won't give you the same effect as soapstone will. The brazillian multicolor on the floor -
The citrus cleaner to remove grout haze should not hurt the slate. It then should be cleaned thoroughly (preferably by a professional and have a topical sealer applied. You choose based on how glossy you want the floor to be. Regards Steven, Expert Panelist
R4: If you want you can use a penetrating sealer. I think you would like it left dull. You can make it wet looking by applying a surface coating sealer. Play around with your options to see what you like best.
Dana, Yes you should seal the multicolor slate. I like a surface coating sealer myself. It brings out the colors and I know that there are colors in that slate. First of all the Tile installers should not leave a haze of grout on the tile. They need about four clean sponges to do about every 1000 sq.ft. of tile. They should change there water regularly and sponge down the tiles about three or four times after grouting. This will get most of the grout off the tiles. Do not hire lazy tile installers. So with that said you do not need the citrus based cleaner.

Dana, everyone is going to have their opinions on certain materials. Please do not use bAbY OIL. baby oil is too greasey. If you have multicolor on your floor then you should have the black from brazil. Although, you can get the other four slates from brazil in slab form. I am an expert on these topics because I have all the slate slabs here and that is what we use them for is for countertops. We only use Mineral Oil from the local pharmacy. Remember that you have a slate countertop and the word Patina is used on Travertine's and marbles. Your Slate will not Patina. I do not know who told you that but they are wrong. That is all I do is just wipe it down with a damp rage. Nothing else. If etching does happen then you can lightly sand it out and put more mineral oil on the surface. It is just that simple. best Regards, Stephen, Canada, Expert Panelist
Q 3024: I'd really appreciate your guidance. We just purchased a 40yr old home with a greenish slate entry way, it has quite a few stains...any suggestions? Robyn, Oct 17. Reply

R1: Dear Robyn: Yes: GET RID OF IT! Maurizio, USA, Expert Panelist
R2: Robyn, I apologize for Maurizio response. He just don't like slate. With the stains just try to strip the sealer off if any. Then bath the slate in muratic acid 50% with water and then reseal the slate with a surface coating sealer. best Regards, Stephen Canada, Expert Panelist
Q 3036: We have a black slate hearth and I was wondering if I could paint it a different color. Sharon, Oct 18. Reply
R1: I will not suggest it but yes people do paint over the slate. I cannot see why you would when the slate is worth about $40 sq.ft. and will add value to your home but the paint will decrease the value of the slate. best Regards, Stephen, Canada, Expert Panelist
Q 2316: I can't believe this happened! I hadn't seen your site, and cleaned my slate tile with regular over-the counter cleaner w/a citric acid base. by the way although it is very expensive here to have this installed, my professional installer had never installed slate in a bathroom before, I found out later, and thus he has no information.
Apparently I shouldn't have used honed black brazilian slate in the shower and bathroom in the first place? 
Apparently an impregnator should NOT have been applied?
The impregnator was the only sealer used for the grout as far as I know. Is that enough? 
I had been afraid to use anything on the slate, and thus it needed cleaning badly. I had a left over piece and put the cleaner on it several times over several days and nothing happened. Alas, other sections of the tiles reacted-I can see that sections reacted and then a swirl of a slightly different color does not react-even an etched drip mark will stop at a color change. Overall I ruined parts of only several tiles and not everything. It's the horrible streaks down sections of some of the slate that are the worst-and it is honed, so I can sand.
So, what issues do I have due to the impregnator being used-or is that okay?
I will try the sandpaper (and find out what a right angle sander is?) --and mineral oil, at least on the walls...probably too slippery on the floor?
What do you suggest for cleaning the white marks left when water dries? And what is best for cleaning the red fungus that will grow after a few weeks...? We have a Fred Meyer and a True Value hardware store, I'll look for Stone Cleaner, but are there sources to purchase by mail that is my only other option? 
I'm worried about cleaning the glass around the shower (vinegar and water are suggested for the water marks) and the toilet (generally something with bleach)? Thank you. Sharon, Alaska, July 27, Reply
R1: Dear Sharon: It looks like you've a nice little mess in your hands! I don't know if brazilian slate needs to be sealed or not. Usually dark-colored slate does not, but "usually" doesn't mean all the time. What is for sure is that you can't use an off the shelves cleaner,  especially with citric acid in it. 
but let's take one thing at a time. You ran some test on a spare tile, I understand. Now the question is: Had that spare tile been sealed? If it wasn't and did not adversely reacted to several applications of the cleaner, while the tiles on your shower stall did, it could very well be that your slate did NOT, in fact, need to be sealed and the etch marks are on the 
sealer, not the stone. That would be good news, because it would only take the application of a Methylene Chloride-based paint stripper to solve your problem without sanding (no stone cleaner -- including mine -- would ever do! They will only help you with your future routine maintenance requirements). If not ... well, I'm afraid that wet sanding would be your only option. Yes, you would need a variable-speed right-angle grinder / buffer with a special 
attachment and special sandpaper to do the job. You would then finish it up with application of a good-quality stone color-enhancer (it does a better job, and more permanently that mineral oil) to bring the whole thing back to a nice, uniform black finish. For more info about right-angle grinders, etc., send me an E-mail at info@findstone.com.
The grout in a shower stall doesn't need to be sealed. However, now that's sealed with a stone impregnator, that's it, leave it alone. About the red fungus issue, sorry, but I really don't know what you're talking about. Maurizio
Maurizio, Thank you for all the information in your column! I've "lemon tested" my blue Pearl granite and it passes just fine! Well, I think so. There are NO white marks left at all, does not seem to absorb at all-yet, it's hard to tell, but if you look in the light right, there may be some spots on the surface that are no longer shiny. I think that the spot where I make coffee has some of these marks on the surface as well  which makes sense. They appear to form a random pattern and are very slight-but perhaps I do need the impregnator after all?- The counter has impregnator on it-but it's the kind that must be replaced in one to three years (Stone Tech), so I figure it'll wear off and I should just leave it? Then perhaps, should I apply your impregnator? 
I've entered a question (Q 2316)--about the slate I etched with citric bathroom cleaner. 
I have three additional questions: 1. You often refer people to contact you directly with instructions for "re-honing" or polishing etched surfaces. Can you send me this information?
2. I have "etched" a practice tile from the honed slate (not treated with impregnator)-and see that it is NOT the impregnator that is etching, although I ONLY was able to etch a VERY small section-even with straight lemon juice, the rest of the tile isn't at all as sensitive (does absorb the lemon juice leaving a darker spot temporarily only, AND I've tried wet/dry sand paper-I started with 400 grit which took out the etched spot just fine and went to 600 grit. My slate must be fairly finely honed, since it appears I ought to go even finer to avoid the overlapped sections with scratch marks? (I tried brasso, since it was a practice tile, to see if a finer polishing would harm it-and that does look to be a bit finer than the surface I have-looks a little polished (even after washing it off with soap-it must have some oil in it as it also deepens the slightly whiter sanded area just fine). Is there something I should use besides finer sand paper? I see that there are Marble Refinishing Kits at our local store, although they are very expensive? Thank you for this information, via the aw site-I see that I have NOT ruined my tiles forever :-) 
3. Some sites suggest that a dilute solution of Ammonia and water and/or bleach and water might work just fine as regular cleaners for slate, is this true? 
4. I have also run into folks who recommended pH neutral isopropyl alcohol and water (50/50 solution) for the granite counter top (and also the slate?). It seems to be working just fine on the blue Pearl-attacks the grease and dirt with no streaks (also does a nice job on the stainless steel appliance front). Do you see any problems using this? Thank you Sharon, Alaska
R1: The dull areas where you made the coffee, etc. are probably due to the presence of the sealer. If It hadn't been "sealed" (actually, it was never sealed, because no sealer ever went IN that stone!) you wouldn't have the problem. So, either you remove the sealer using a paint stripper based on Methylene Chloride (which is what I would do if it were my countertop), or you wait until it wears off (3 or 4 years, maybe).
As far as re-honing your hone-finished slate, you should be using metal grade sandpaper, 400 and 600 grit, using it wet and, possibly, with a low speed right-angle grinder / polisher, to have a very uniform and scratch-free final result. Forget about the marble refinishing kits for your slate.
I don't know the long-term effects (if any) of bleach and ammonia on slate, so I won't make any statement, but, as a gut feeling, I just don't like the idea. Maybe who told you that has a better knowledge of chemistry applied to slate than I have. The Isopropyl Alcohol solution should be all right (by the way, all alcohols are 
pH neutral!) Maurizio, USA
R2: The product that this customer has is black honed slate from brazil which has Iron Pyrite through out the stone. The Citric acid base will etch the stone and no slate is not like granite. If the product is in the shower then you have to put a surface coating sealer on the stone. There are swirls in the stone which looks nice. You will get a Grey and black swirl because the Grey slate comes from the same quarry so you will get a bit of both in the stone. Impregnator was good to use but GlazeNseal would be a better company to use. They make sealer for slates and most of the rest of the sealers on the market are for limestone's and travertine's like Stonetech, Miracle, SCI. The white marks left by water everybody should know that is the Hard water Calcium build up. Limeaway or CLR will do the trick. Red Fungus should not grow if the shower is kept clean and washed down everyweek. With the question about sanding we use wet, light grit sand paper and lightly sand it out. In my bathroom I just use luke warm water and a light detergent. No Abrasives like Ajax or comet. Slate on the countertop will etch if sealed with a penetrating sealer or left unsealed. We always suggest using mineral oil or even better a surface coating Acrylic based sealer. best Regards, Stephen, Canada, Expert Panelist.
Q 2250: I have a piece of rough (unpolished) green slate, which I use as a table top. Someone left a bottle of massage oil on it, and it left a stain. Is there a way to remove it? Robert, July 18, Reply
R1: Dear Robert: Yes. You have to poultice the stain out using acetone. Maurizio, USA 
R2: Try lightly sanding it out. If that does not work and your table is not sealed then put a light coat of mineral oil on the whole table every month or every two weeks. Every try Oil, Gas, and Water in a glass. All the rest sinks like the stains and the oil comes to the surface. It works and will go away after awhile and you won't have any scratches from sand paper. best Regards, Stephen, Canada, Expert Panelist
Q 2219: I have domestic autumn slate installed in my master bath shower. There is a wet look lacquer that has been used as a sealer for about 1 year. Soap scum and calcium deposits warrant a very good cleaning. What is the best way to strip this? What is the best sealer to put on slate in a shower that will be used daily? For future reference, what is the best way to clean slate? Veronica, USA, July 15, Reply
R1: Dear Veronica: To remove the current topical sealer you'll need to use a potent paint stripper based on Methylene Chloride (anything else won't cut it). After that I don't know the answer to your other questions. I'm not that familiar with slate and, most importantly, I don't believe in shellac-type topical sealers. Maurizio, USA
R2: You can use Limeaway or CLR to get the Calcium deposits off and there are some products on the market like a solvent based striper. That will work. Got to a local hardware store or a concrete factory and look for a concrete striper. It will do the same. It will do almost the same as GlazeNseal wet Look. best Regards, Stephen, Canada, Expert Panelist
Q 2208: How can I refinish an interior slate floor that has had little or no maintenance for 10 years. Plenty of scuff marks, liquid spills and just plain dirt. Will sanding have any adverse effect on the slate? I was told a mixture of turpentine and linseed oil may work. What proportions of each are to be used? Any suggestions would be welcome. Thanks,  Nick, July 12, Reply
R3: You will have to give the floor a good cleaning. I suspect you have a textured floor which we use a steel brush to actually loosen up the dirt that is stuck to the floor. Then if it has been sealed before you may need to strip the sealer and then reseal the floor. Elbow grease works best but if you have a big floor then rent some equipment that will loosen up the dirt. Please DO NOT USE Turpentine and linseed oil. Find a concrete sealer or an acrylic base solvent sealer and that should do the trick. best Regards, Stephen, Canada, Expert Panelist
R2: The first thing we need to do is to know what turpentine and boiled linseed oil is used for. It is to color enhance the stone or bring out richer color tones seen when wet. When sealed after application it can be durable for an interior low to medium traffic area with proper maintenance.
To deep clean the floor here is one simple approach:
Start by renting a low rpm buffer and a scrubbing attachment with lots of water and a neutral pH stone cleaner. 
Rent or purchase a wet/dry vacuum. 
Purchase a neutral pH stone cleaner. 
Mop the area with lots of water and a neutral pH cleaner (make the area real wet.) 
Scrub it with the buffer. 
Remove the dirty mixture with the vacuum. 
Repeat until clean. 
You may find the scuff marks don't come out, you then decide if you want to color enhance (linseed & turpentine) or buy one off the shelf, and seal the floor.
Get in touch directly with me or Maurizio for more detailed responses. Regards, Steven, USA
R1: Dear Nick, If the scuff mark is created by shoes surface traffic it can be cleaned up easily by an alkaline cleaner with a soft brush, Clean the residue before it dries and rinse with neutral cleaner.
I suggest to seal it with Sealer; There is sealer available in Low sheen with slight enhancement (Slate Sealer) or if you prefer Enhancing with no sheen result. Importance of Sealer; U. V. Resistance & breathable.  I hope this helps. best regards, TAN, Singapore.
Q 2169: I have a slate floor that is about 50 years old and am interested in procedures or products that we can use to restore them. They are in fairly good shape but probably have many coats of wax etc. that make them look old. We are planning to refinish the adjacent hardwood floors and thought that sanding the slate might also make sense. Thanks! Jay, July 8. Reply
R2: You have to strip your sealer/wax off of the slate. You should have a textured floor and that is what you want. If you do want a honed surface the you still should strip the sealer and use Diamond pads instead of sand paper to achieve a honed surface. best Regards, Stephen, Canada, Expert Panelist
R1: Dear Jay: No it won't make any sense at all!! Have your slate stripped from any coating of old wax by a professional janitorial company. Maurizio, USA
A 2132: I have some Lilac Mist slate Iit looked fine when purchased but after sealing it, little greenish spots appeared it looks like its coming from within the stone... What could this be and how can I fix it? Tbear, June 28, Reply 
R2: Lilac can either be the lilac slate or Indian Autumn from India. Mother nature made the material so what is in the stone is in the stone. It was up to your installer to look and inspect the stone before installation. but some green is in the stone. Now if the is something between the stone and the sealer then you should strip your stone and give it a bath of muratic acid which won't hurt because we do the same all the time. best Regards, Stephen, Canada, Expert Panelist
R1: If you think you have something developing, wash the stone with 1 part to 5 part muratic acid. Rub with a bristle brush and rinse thoroughly. Follow all safety instructions for use. It will require resealing when it is complete. Regards, Steven, USA
A 2116: Slate seems to be a tiny market here in Northern California therefore knowledge about it is scarce & complicated by the fact that "Slate" is a generic term used to describe any shale type stone. Ever since American-Olean went out of business, I have not been able to find professional support for Northeastern gauged slate. The quarries we buy it from, sell it.....period. 
Consequently, something goes wrong with every job. We continue to use slate because it works really well with our radiantly heated designs. My current black slate floor installation went very well but a few months later the clients cleaning people were able to turn it gray with white spots with whatever method they used to "clean" it. Do you have cleaning products and procedures for slate? At the core of the cleaning problem I believe is the alkaline nature of the water and the soil in this part of the country (northern California). Thanks, Mark, June 26, Reply 
R1: Dear Mark: I'm glad to hear the good news: "Slate seems to be a TINY MARKET here in Northern California" Thank goodness, I add! You can get my free maintenance guidelines for residential stone installation by hitting the link at the bottom of this in advice section of left side bar. Treasure them; you'll be glad you did! Whatever is good for marble, is good for slate, too. but do you know what really baffles me? It appears that you've been installing slate for quite a while, but never bothered -- at least until now -- to find out what kind of advice to give to your all too important customers about its proper maintenance. And now you blame the cleaning people! ... Are they supposed to be the ones who have to know about natural stone and its requirements? As far as a solution to the problem you're reporting, there's none. Maurizio, USA
A 2114: My 2 1/2 year old double sink countertop is a slab of green slate. Unfortunately, quite a few white stains have begun to appear and rapidly spread around where the faucets connect to the slate. What is the best thing to use to remove these stains? Thanks! Dana, June 26, Reply
R2: All you have to do is shut of the water and remove the taps and just use Lime away or CLR. Then you should use Mineral OIl regularly to seal the countertop if you do not have a sealer on it already. best Regards, Stephen, Canada, Expert Panelist
R1: Dear Dana: Nothing, really. If it's an accumulation of mineral deposits, you could not use any such product like "Lime-away" or the like because it would damage your slate permanently. Slate is not the right stone for countertops. Get rid of it and use something more practical. Unless, of course, the dealer who sold the slate to you (and made good money in the process) has some secret solution to your problem. I mean, they probably did some serious homework before they started selling slate! ... Maurizio, USA 
A 2096: We have raw gray slate that we want to use to make a patio. It has been outside for 2 yrs. and has turned a greenish color. Can you tell me how this can be cleaned to make it look like it did originally? Thanks, Sharon, June 20, Reply 
R2: 50/50 Muratic acid will remove the mildew and any staining. I don't know about the greenish color but just try a test tile first to see. best Regards, Stephen, Canada, Expert Panelist
R1: Dear Sharon: It's most likely mildew. Try to power-wash it with a solution of water and bleach. It should work. Maurizio, USA 
A 2095: We moved into our first house about a year ago; it has a slate shower. As time has gone on, I've become aware that half of the slate seems to have been finished with some sort of protection, while the other half has started to dust up or flake. because I'm new to the house-owning game, I'd like some advice on what to do. Is there a product used specifically for slate to coat it? Should this be done yearly? Should the entire shower be redone? Can I do this myself or is it wiser to get a pro to do it? I'm also interested in any cleaning tips people might have; at the moment I scrub the floor and walls while I'm showering, using no cleaner of any sort. Is there a special slate cleaner? Thanks, Nicky, June 20, Reply
R2: First of all where is the Dusty looking slate, On top or on the bottom. The sealer person might have sealed the bottom of the shower to protect it from the water and left the top unsealed. If it is the othe way around or something different then You might have some layers flaking off of the slate. In a case like that we wash the slate really good and left dry. Put a heater in there. There maybe water behind the slate but you and I don't know and lets not think that until you find out that is the case and if it is then you may have to reinstall the slate in the shower. but for now, make due with what you have. Let the shower dry and put two or three coats of an acrylic solvent based surface coating sealer on it and do this Once every year or two. best Regards, Stephen, Canada, Expert Panelist.
R1: Dear Nicky: "dust up and flaking", uh ... I'm afraid you've got water behind those tiles. 
It's terminal. Waste no time and redo the entire shower stall. Do get a pro and choose a better stone than slate for your shower (marble or granite, perhaps) Make sure that the professional installer is not a "Michelangelo" and that the installation is not done "butt-joint". Maurizio, USA 
A 2069: I recently purchased a home in boston. The master bath has a black (flat) slate counter top. (It took me awhile to determine that it was slate - so go gently this is new to me). The counter top doesn't seem to have any sealant. Water stains the countertop along with any product that hits the surface. I'm faced with the challenge of: 1) properly cleaning the counter to remove the stains and 2) sealing the counter top so to prevent future stains. I do not want to change the surface tone or shine. I love the charcoal grey flat color. 
Thanks for tips on both care questions and product recommendations. Also any information on service providers in my area would be happy. Hab, June 16, Reply 
R2: Disregard everything you heard about slate for countertops and listen to me. The water stains can be cleaned by LimeAway or CLR. For tough stuff use Muratic Acid 50/50. To seal the countertop the is black maybe from brazil ,Mineral Oil once or twice a month and that will make you happy. best Regards, Stephen Canada, Expert Panelist
R1: Dear Hab: You have a third option, which is the one that I recommend wholeheartedly: 
GET RID OF THE SLATE COUNTERTOP and replace it with a charcoal granite instead (it will be polished, though.)
Those "stains" are not stains, These are etch marks and only a proven professional stone refinisher will be able to repair them. What's more, they will happen over and over again, no matter what kind of "magic" sealer (including my own!!) you will try to treat the stone with. Maurizio, USA
A 2008: Hi, I used "Zap" tile cleaner on our slate flooring, and now our tiles have white discoloration everywhere, and the tile scratches easily. I tested a small area first, and the cleaner seemed to work beautifully, so I proceeded to clean the entire kitchen. After about a day or two, the irregularities began to appear, and have gotten worse over time. What can I do to repair the tiles? Janet, June 3, Reply
R2: I can tell that Maurizo, Does not like slate. First of all there are options. I will give you one. Strip your floor with a solvent stripper like a concrete stripper. Then let dry and reapply a surface coating sealer for Slate from either GlazeNseal or Universal Slate or find an Acrylic Solvent based Sealer or a good concrete sealer. Oh!, Throw away your Zap! best Regards, Stephen, Canada, Expert Panelist
R1: Dear Janet: Rip those tiles out and, now that you've learned the hard way that you do NOT want slate in a kitchen, install another more suitable material instead. At first it may sound too a radical solution, but, trust me on this one, it will be the only one that works. It will save you a lot of money (by not attempting useless solutions), not to mention the most important factor of the equation, that is your mental health!, Maurizio, USA
A 1947: I recently acquired a slate (type yet to be determined) fireplace mantle (complete). The slate is black (very dark gray) and has fine engraving on it's vertical surfaces. I have been told that it comes from the east coast and was created circa the 1880s. Sometime after it's manufacture someone painted gold veins (faux granite, I suppose) all over the surface. Sometime later, someone painted with a medium green low-gloss enamel (lead ?) paint. There may be other coats under the green. I don't know this yet. I would like to take the slate back to it's natural color and state. How do I clean the layers of paint off without damaging the integrity, condition, surface or value of the slate mantle? Thank you! Russell, May 22. Reply
R2: Slate is like a baby, It is harder than you think. You don't have to be very very careful with it. Use a paint stripper because that is what you have to remove. Then use a Solvent Stripper maybe it is the same but if the stone was sealed then you should remove that too. Remember that you will have to use Elbow Grease. Once you remove everything then you can seal the slate with any sealer you like to give you the desired finish. I like the wet look. best Regards, Stephen, Canada, Expert Panelist
R1: Dear Russle: Very, very, very, VERY carefully!! Use a paint stripper based on Methylene Chloride., Maurizio, USA
A 1866: Dull: I have a dark gray/black slate floor in the entry way of my home. The home is 40 years old. We have lived there for 20 years. The floor is in need of sprucing up. It looks dull and is off-color in some places. I have been using a retail cleaner and sealer (wax) for slate approximately every 6 weeks. Would it be wise to have it commercially resealed at this point? What about buffing with a rented electric buffer...would that help. Anything else that you could suggest to improve it's appearance? Thanks,May 15.Reply
R3: Just Strip the sealer off the floor and reseal the slate. best Regards, Stephen, Canada, Expert Panelist
R2: Dear May: Keep using what you've being using. Maurizio, , USA
R1: It depends on what you want the floor to look like. For instance, if the material retains its texture and you want it to look glossy, you then are looking for a topical coating. Many of these need to be buffed after application. If you like the look of the wax, but don't like the six week interval, then you may want to clean the area with a neutral pH cleaner, color enhance with a good color enhancer, and then coat it with wax. With your concern about its appearance a buffer is a good thing to have. Many families in Europe with stone and tile floors have them. Regards, Steven, USA
A 1860:What is the best way to clean slate floors? They are old chalk boards that we've cut and laid. They are dull. Any ideas? Thanks,Jody,May 14.Reply
R2: You have to seal the slate with an acrylic surface coating sealer to bring our the color like when it is wet. Then cleaning is a breeze. best Regards, Stephen, Canada, Expert Panelist.
R2: Dear Jody: Try treating them with some mineral oil and see how it grabs you. Maurizio, USA 
R1: It may be that cleaning is not the problem. You may want to get them professionally honed. From there, it becomes a cleaning and maintenance issue. Regards, Steven, USA
A 1847:My fireplace has slate on the raised hearth. The slate is marked (crayon, scratches) also there is what looks like an oil stain blotch on it. Do you know how I can go about cleaning this up. I have tried water and a scrub brush and it lightened it a little (the oil looking blotch). Thanks, Galotti, May 14. Reply
R3: Maybe try a light sanding if nothing else works and reseal the slate. best Regards, Stephen, Canada, Expert Panelist.
R2: Dear Galotti: The Crayon should not represent a problem. You should be able to get rid of it by scrubbing it off with a brush and warm water (the warmer the better). For the oily stain, use a poultice with talc powder (baby powder) and acetone. More than one application may be needed, but if the stain is not too old, it should work. Maurizio, USA
R1: Try a poultice on the oil spot. It is important to correctly analyze what caused the spot in order to use the correct active ingredient for the poultice. Use some diatomaceous earth and mix with acetone, thickly cover the spot and tape plastic over it. Let stand for 24 hours remove the poultice and vacuum the spot, inspect and reapply until the spot is gone. You may then want to impregnate the slate. Regards, Steven, USA
A 1838:I have a new natural slate floor and shower in a hall bath which has been sealed twice (within the last 2 months) with a penetrating sealer. I spilled a few drops of liquid antibacterial hand soap on the floor and it stained -- It will not come out with warm water. what else will work? also, the shower floor is 4x4 tumbled slate -- any suggestions as to how to best keep it clean and free from soap scum etc. i do my best to wash it down with the water after each use, but over time there's bound to be buildup. please help. sphlah, May 14. Reply
R3: You have a penetrating sealer on the slate. When you wet the stone so the stain disappear. If it does then you need to seal the slate with an acrylic solvent based sealer. For your shower floor just maintain it with a little bit of sealer once a year. For water stains and Calcium just use Limeaway or CLR and Elbow Grease. best Regards, Stephen, Canada, Expert Panelist.
R2: Dear Sphlah: Saying "Natural slate" you're saying absolutely nothing (actually, too much!!). What happened with the spilling of the anti-bacterial soap is that it has etched (corroded) the very surface of the stone and, since I assume it's a natural cleft finish, there's nothing that anybody can do to fix the damage. Such surface damage has absolutely nothing to do with the rate of absorbency of the stone - but with it's natural chemical makeup - and so the application of an impregnator (which deals with porosity of the stone by reducing it), no matter how good, is totally useless to prevent what happened. Let's say that's the wrong stone for the wrong application. Maurizio, USA
R1: Many slates will require multiple applications of impregnators. i.e. one per day for 5-6 days per application. From there, it will need to be redone as necessary. The real dilemma is how to properly clean and maintain the installation. Write to Maurizio for instructions. He is happy to help. Always pay attention to the grouting and caulking as well. Plan on touching these up when you first see a separation. Regards, Steven, USA
A 1803: We have a slate entry with brick border an are about to seal the surfaces. Would you Please advise which of the many products- is the preferred item? big difference in price and I wonder if one gets what one pays for. Also, the brick driveway needs sealing as well. What do you advise for that surface? Thanks, Alan, May 14. Reply
R3: I fortunately know how to remove residue of old sealers and reapply new coats. if it was my floor and driveway I would want a wet look because of the properties of a surface coating sealer. The water will bead off. You will have to reseal the driveway once a year or two but inside you might not have to for a lifetime, it depends if the floor look dull to you. best Regards, Stephen, Canada, Expert Panelist
R2: Since it is outside, what are you trying to achieve? All the types you mentioned will help some. You should test each on a sample and see which one was easiest to apply and gave you the look you want. You want something that is UV stable. Plan to do this a couple of times per year. Regards, Steven, USA
R1: Dear Alan: No matter how expensive, "permanent" topical sealers are a NO-NO in my book, on cleft-finished slate. They will wear down eventually, of course, but you will have a very hard time to find anybody that will know how to remove the residue of the old sealer before applying a new one. I would encourage you to use a janitorial-grade topical finish (thermoplastic or metal-interlock). At least they can be maintained and stripped easily when necessary. Maurizio, USA
A 1780: Have a black slate hearth. Had a bad fire in my house; walls down, etc. Some kind of animal (cats?) got in the house and peed on the slate leaving white marks. I've tried everything to clean it but nothing helps. Aside from professional help, is there anything I can do? Maria, May 5. Contact
R3: Try pouring pure Muratic acid on the slate and adding water. (Do not breed in the acid----bAD) scrub the slate down good. The acid should absorb in to the stone pulling out any oders. Then you should seal it with a surface coating acrylic solvent based sealer. best Regards, Stephen, Canada, Expert Panelist.
R2: beside re-honing the etched spot try applying mineral oil periodically. Regards, Steven, USA
R1: Dear Maria: There's no guarantee of a final result, but before you call a pro you can try 
the following, providing that we're dealing with a smooth surface (like a black-board):
Use wet sandpaper (metal grade) starting with a 100 / 120 grit, and go all the way up to 400 and, if available, 600 grit. It will take a lot of patience. Each grit must be worked slowly and thoroughly (figure approximately 5 minutes each grit) in the constant presence of water. Each grit will have to overlap the pattern generated with the previous one. Once 
you're finished with the honing process and your surface is nice and smooth, you can obtain depth of color to blend in with the rest, by dressing the stone surface with baby oil. Let the first application dry completely (one day or so), then apply again if necessary. Maurizio, USA
A 1748: HELP! I have a slate floor in the bathroom which should be black but is a 
nasty grey and covered in white marks
. So far I have cleaned, sealed and tried acid all to no avail. Any ideas? Punani, April 22. Reply
R2: Strip the floor and let dry. When you wet the floor it should be what you want. If this is the case then seal the floor with an acrylic solvent based sealer. best Regards, Stephen, Canada, Expert Panelist.
R1: Yep, Call a professional refinisher. You have etched the surface and it needs to be rehoned. Regards, Steven, USA.
A 1737: Can you suggest a product I can use to clean a slate heart? Thanks, Marion, April 20. Reply
R1: Q) What is wrong with it? Generally use a neutral ph stone specific cleaner for everyday care and specific products for specific stains. Regards, Steven, USA
A 1712: We recently installed a multi-color natural slate 16x16" in our home. We have sealed with Stone Enhancer - which says it will provide a "wet look". We have put 2-3 coats on but once it dries, it returns to the dull look. I want it to look the way it does immediately after applying the Stone Enhancer - i.e. the "wet-look". Do you have any suggestions? Judy, April 15. Reply
R3: Stone Enhancer no does not work. ask for a sample of the wet look Lacquer. best Regards, Stephen, Canada, Expert Panelist
R2: Dear Judy: Change color enhancer. Maurizio, USA 
R1: You need a different product. It will be a top coat that is specifically labeled as shiny. It will not be very long lived though. Regards, Steven, USA.
A 1649: Wow, I am impressed with your site and hope you can assist me. I recently had green American slate installed in a shower, both the floor and walls. It now appears after about three months of usage that the installer sealed the floor, not the walls. There are, what I think, soap streaks appearing on the shower walls. I tried cleaning the walls with a stone soap cleaner purchased at Home Depot, but it didn't work. I don't think that the streaks are hard water deposits because I have a water softner. Any suggestions? Ric, April 4. Reply
R2: Maybe it is Calcium. Try Limeaway or CLR. Make sure you seal your whole shower. You will save money in the long run and not rip out your shower. best Regards, Stephen, Canada, Expert Panelist.
R1: Hey Streaker ---- I've done plenty of slate showers. They may have not buffed the walls when they sealed the grout. This will cause streaks sometimes, I had to tear out a white marble shower once because my guy failed to buff the sealer into the faces when he applied it to the grout joints. You may be able to use impregnator (sealer) again and get rid of the streaks Try one tile see what happens. 
Call the company who did the installation and find out what they sealed the grout with, That might solve the question of what to use to try and eliminate the streaks. Soap won't stain slate, or I would never have had so many happy customers. Tile Guy, USA.
A 1581: I have installed a black slate hearth on a fireplace. I cleaned the slate with stone cleaner, tried soap and water, and plain water. Then it was sealed with stone sealer. but there is still some discoloration in the slate (some gray areas). The client would like the hearth to be a consistent shade. Can anything be done to correct this since it has been sealed. Can stone sealer be tinted with some type of dye before applying another coat? George, March 23. Reply
R2: That is just in the stone. You cannot get rid of it. That is the beauty of Natural Stone. In England and U.S.A. and Canada People used black shoe polish. I would not sit on the hearth after that though but Ya that is what they used to do. best Regards, Stephen, Canada, Expert Panelist
R1: Dear George: Now that you've applied an impregnator (which is not supposed to be applied on black slate to begin with), you will have a hard time to rectify the situation. I'd suggest you strip the sealer off (thank goodness it couldn't go inside the stone) by using a paint stripper based on Methylene Chloride. After that, you can apply a so called Stone Color Enhancer. In the old days black slate was treated with mineral oil (baby oil will do just fine!), but then, there weren't so many salesmen back then!!  Maurizio, USA
A 1447: I have just had a black honed slate worktop fitted in my kitchen. The fitters used a coating sealer on it without asking me and I have asked them to remove it (as it now looks like formica rather than slate!) and use an impregnator. They have used 'Lithofin Wax-Off' to remove the coating sealer but there is still a speckled finish on the slate and I don't want to use the impregnator until it's completely stripped and cleaned. Any idea why there are still remnants of the coating and any ideas for what I should use to strip and clean it properly? Also, I was going to use either Lithofin or HMK S34 impregnator (both with Silicone). Is there any difference? Finally, I was then going to use HMK protecting paste on top - do you recommend this? Many thanks in advance. Julian, England, Feb 16, Reply
R2: Strip the sealer with a solvent stripper and just use mineral Oil one or twice a month. best Regards, Stephen, Canada, Expert Panelist
R1: The short answer is no. The slate is not very absorbent. The impregnators help it repel oil and water from seeping in. I believe that a coating as the fitters used was entirely appropriate. Ask them if they have something with a low gloss. If not then have them rehone the surface to remove the coating. You will then have slate and only slate. It will scratch and patina. If you ever want to darken it use mineral oil. Steven, USA 
A 1426: I have recently made a slate table top using honed black Italian slate. I am having a nightmare trying to seal it - I have used Lithothin Stain Stop but this still allows lemon and white wine to mark it. I have also tried linseed oil mixed with white spirit but with no joy. I keep getting White marks keep appearing. 1. How can I remove these? 2. How can I prevent it happening in the future? - i.e. can I seal it to prevent this? Regards, Rebecca Feb 12. Reply
R3: Try to lightly sand the stains down. Or try Muratic acid in a small dose with water. You can seal the slate with a mineral Oil once or twice a month or permanently put a surface coat of an acrylic solvent based sealer on it. It will etch a bit into the sealer but you can catch it before it hits to slate and just reseal and touch up in the area. best Regards, Stephen, Canada, Expert Panelist
R2: Hello Maurizio, May I just agree with all you have said. There seems to be an obsession with sealers. If you don't want stains, buy Formica. The advice you have given is sound and honest, Rub it down and slap on some oil. Roy, UK
R1: Dear Rebecca: You've got it all and hopelessly wrong!
1. black Italian slate -- very much like its New England counterpart -- doesn't take any sealer to begin with (too dense).
2. A penetrating sealer -- any penetrating sealer -- (which in your case won't penetrate; but that doesn't mean anything, besides a waste of money and time) does one thing and one thing only: it helps prevent staining by clogging the pores of the stone. No other protection whatsoever, other than that..
3. Lemon juice, drinks, etc. do NOT stain slate (nothing does!). They etch it, is their acidity corrodes it, and there's no sealer in the entire world that even advertises to help prevent these kinds of surface damages.
4. I the surface of the slate is smooth (like a chalk-board), then you can fix those damages by wet-sanding them starting with a 120 or 240 grit and go all the way up to a 600 grit (you'd need a variable speed right-angle grinder/buffer). Then blend the finish in by rubbing a little bit of mineral oil (baby oil will do just fine). If the surface has a "cleft" finish instead (natural from the quarry), there's nothing that you can do.
Conclusion: wrong stone for the wrong application, under the assumption that a "miracle-in-a-bottle" stone sealer could solve the problem. Maurizio, USA
A 1378: If you do get scratches on slate, is there a way to make them less visible? Jan 28. Reply
R4: Just a touch up of sealer. If you did use a wet look sealer. If the slate is on a countertop then use mineral oil if unsealed. best Regards, Stephen, Canada, Expert Panelist
R3: If the slate is unpolished, then use a light sandpaper to remove the scratch. If the slate is polished, the same process may be used but the area will require repolishing and it is difficult to match the level of gloss. Regards Arun, India, Reply 
R2: Use mineral oil or lightly sand the scratch and use mineral oil. Regards, Steven, USA  
R1: Yes, with baby oil (or any other mineral oil). Ciao, Maurizio, USA,
A 1351: We recently purchased a 1965 home that has slate flooring in the foyer. The previous owners had applied several coats of floor wax to the slate which has now yellowed. What is the best method of removing the wax from the slate floor? Thanks! Pat, Jan 21. Reply
R3: The slate is not yellow the wax is. The same wax they use on peel and stick vinyl floor tiles. Strip the wax ALL off with a solvent based stripper or concrete stripper. That should do the trick. Then reseal it. best Regards, Stephen, Canada, Expert Panelist.
R2: Dear Pat, Old wax deposits are difficult to remove. There are commercial varieties of wax removing chemicals called strippers. You should use one of them . As the house is old, wax may have penetrated deep in the pores and it may be very difficult to remove the entire wax. Regards Arun, India
R1: Dear Pat: Get hold of a janitorial company that does stripping and waxing and hire them to strip your floor. Maurizio, USA,
A 1295: I am looking to find a product called Dress Slate. I sealed my interior slate floor with it 18 years ago and it has lasted this long. I would like to do it again, as the slate is beginning to look dull, but I cannot find the product and am afraid to try anything else. Jan 2. Reply
R1: Dress Slate is no longer available. There are various sealers available which provide excellent protection .The choice of the sealer depends upon the finish you desire and the use of the area being treated. If you can provide us with more details, we can suggest you the sealer. Regards Arun, India,

A 1204: We recently had smooth slate countertops installed in our bathroom. The installers put on a sealer but it is kind of smeared. Can we clean it off and start again somehow? What should we use to clean it and assuming we can get is clean, what should we use to seal it? Dick, USA, Nov 21. Reply

R4: I actually have to agree with most of what Maurizio's statement. In my case I would strip the countertop and just use mineral oil on it for the rest of it's lifetime. but the product is not from England I don't think. brazil is producing a nice black, Grey, Purple, and Green slate slabs in a honed surface. That is what I think Dick has. If not then the black Slate from Quebec, Canada. best Regards, Stephen, Canada, Expert Panelist
R3: Dick, Call the original installer and have him/her apply another coat of the sealer and not to leave until it is thoroughly dry and buffed. best regards, Steven, USA
R2: I have to assume, for starters, that we're dealing with a domestic slate (from New England). Typically, only these (and the Italian ones) come with a hone-finish. Domestic slate is indeed very dense and its staining is only superficial. It doesn't absorb an "impregnator"-type sealer very well (only in a spotty way, which, I seem to understand, is exactly what happened there). In fact, most domestic slate producers recommend not to seal it. The removal of a sealer is always a difficult operation and there's no guarantee that the whole thing is going to come out in a uniform way. With light-colored stones it's not a real issue (even if some of the stuff remains
in, nobody could tell), but it's not the case here. before getting into the attempt of removing the sealer, I would suggest you to rub some light mineral oil over the surface of the stone (baby oil will do just fine for this
purpose), and see how it looks once you're done. If you have a nice, uniform black surface that looks like velvet, that's the way your slate is going to be at the end of the treatment that I have in mind (baby oil is not
permanent and will eventually evaporate).  If you like what you see, then it's time to try removing the sealer, by using a strong paint-stripper (read the label on the can, it should have Methylene Chloride in it. Nasty stuff: use rubber gloves and keep your window wide open!). Apply it liberally, then, using an old towel, gently rub it for 10 minutes or so, making as sure as possible that you're treating in equal amount of rubbing the whole surface. Eventually, you will wipe the whole thing dry by using a clean towel (which you don't care about). Again, when you dry, try not to be partial! I don't think that the end result is going to look glamorous, but it should be a dark gray. Overall although a little spottyand streaky here and there. It shouldn't really matter (because of the test you conducted before with the baby oil). Now, instead of using a useless Impregnator, you will be applying a so called Stone Color enhancer, the same way you did with the baby oil. The only difference is that the type of mineral oil making the product will not evaporate. Maybe, you will consider doing a couple of applications (wait until the first one's real dry). DO KEEP ME POSTED. I will accept that as legal tender for my advice! Maurizio,
R1: Hi, Use a stripper even a paint remover will work. Then seal it with an impregnator. Pini, USA
Thanks for the incredibly detailed advice!!!!! Dick

Q 1022: Care: Help!  How can I restore luster to a slate floor on the balcony.  It is in the sun and salt air and has paint splattered on it.  It looks cloudy, dull, and lifeless!  It was sealed when it was installed 7-8 yrs ago. Helen, USA. June 27 reply
R2: Try to Strip the paint off and the Sealer with a solvent based sealer. Then Reapply a surface coating sealer once a year or every two years, because the surface of the sealer will wear off over time. It is not hard. Pour the liquid in a tray and use a paint pad to get an even coat. best Regards, Stephen, Canada, Expert Panelist

Firstly you will need to use a proprietary product to strip the old sealer. You can be quite vigorous in removing the paint (?coarse sanding) as it will blend in after re-sealing.  I suggest mopping the floor a couple of times to collect some of the salt from the stone prior to resealing.. Remember to change the water regularly.  Regular application of sealants is advisable (~4years) to keep a protective coating on the slate and cut down on the work in the long run. Jim, Expert Panelist, Australia

A 995: I want to coat slate tiles to render the color of the tiles more uniform. Can you recommend a product to do this? Reg, Usa. May 23 reply

R2: NO because mother nature made the tile and there is no way to change the color. There are slate that are uniform in color but maybe the one that you have is a multicolored slate. Just wet your floor and see what colors pop up at you. You can seal it with a surface sealer. Try it. best Regards, Stephen, Canada, Expert Panelist.

R1: Slate is a natural product and therefore gives you a myriad of colours by design.  Trying to make the colours the same after laying is like making leopard change its spots.  If you do find a product (I don't know of one), it will only give you a superficial colour change that is likely to deteriorate over time. Regards, Jim,Expert Panelist, Australia

A 947 a: I am house sitting a home that has black slate flooring around and on the fireplace hearth.  The water here has much calcium in it, and I had a plant that moistened the hearth slate, leaving a large white calcium mark on the slate.  How can I remove this? Rose, USA, March 23, Reply

: Try Limeaway or CLR in small doses. You will not get this of in one try. Also try a steel brush to remove the hard calcium. Once you have removed it then seal the slate with an acrylic solvent based sealer. That will take care of the scratches. best Regards, Stephen, Canada, Expert Panelist.

R1: If you had so much Calcium in the water in your neck of the woods, you would have to eat it, instead of drinking it! If what you have is really a deposit of Calcium (or any other hard mineral), you should be able to remove it by scrubbing it with some water and "0" steel wool. If it won't come out like that (and I doubt it will), than you have a surface damage, the result of some sort of chemical reaction between the water in the flower pot -- together with the chemicals contained in the dirt and, possibly, some added fertilizer -- and the make-up of the stone. Since -- from what I can understand -- the slate that you have has a cleft finish, as opposed to a
ground finish, you can't regrind it (that would be the only way to actually repair the damage). Let me ask you a question: if you wet that particular area with some water, does the "stain" disappear until it dries? If the answer is yes, try this: Mix some boiled linseed oil with some mineral spirit (both available at any hardware store) in a proportion of 50 / 50, then, using a little rag, wet the stain with the mixture, trying at your best to blend it in with the rest of the stone surface. Repeat if necessary. That should do it. Good luck Maurizio, USA

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