||sandblasting, staining, grout, color
|Q 2348: My wife and I just purchased
a condo on the Gulf of Mexico. A lot of the unit is tiled with
travertine. Many of the tiles sound hollow when tapped with something
hard, and some tiles actually creak when they are walked upon.
Is there a solution short of tearing up the tile and replacing it?
ben, July 30
|R1: Dear ben:
Nope. Maurizio, USA
I would need to sandblast the exterior of the building which is made
of stone with mortar infill and the oak beams inside which are painted
lightly with emulsion and pitted with old (and possibly new) woodworm
exit holes and powder debris in places. basically the beams are sound
however and once the top surface is cleaned off from its emulsion
cover and the woodworm holes I will treat them with a proprietary
liquid commonly available in France.
The question really is based on the cost that the French master
builder is charging to do this job which, may or may not be fair as
I cannot assess it out of ignorance. If I could find - someone
in the trade who could advise on cost it would be helpful. Thanks,
Leo, July 26
Dear Leo: I really have no idea of what one should be charged for
a sand-blasting job
in France. What I do know is that -- if it were up to me -- I would
put in jail, without even the benefit of a trial, all the sand-blasters
of the world. And I would throw away the keys, too!! There are much
better ways to clean exterior stone surfaces without badly damaging
them (all too many times for good). Maurizio, USA
My daughter colored her hair and got stains on my sink. What
can I use to get the stain out? barbara, July 23
Dear barbara: You want to try a poultice with talc (baby powder) and
Hydrogen Peroxide (Salon grade, 30 / 40 volume), Maurizio, USA
|Q 2276: I have a
stone table in the dining room, but it is so porous that it is getting
stained. What do your recommend we seal it with so it acts more
like tile when we use and wash it? Thanks, Keith, July 22
Dear Keith: Tell me what stone it is and, most importantly, describe
how the stains look
like to me. Only then will I be able to tell you what to do. Maurizio,
|Q 2258: Hi! I recently
purchased a table from a school science laboratory, and I'm told that
the table top is slate. Since I am very unfamiliar with this material,
I have many questions. First of all, how can I tell if the top
is really slate? And, if so, how can I tell if it's a natural
slate or some type of compound? My main concern at this point is that
it has some type of black rubberized protective coating which appears
to have been painted onto it, and I'd like to remove the coating without
damaging the "slate" underneath. I have scraped off some of the coating
in order to examine the stone beneath it. It is a smooth black/charcoal
gray stone with a rather dull finish. The coloring is consistent with
little or no color variation. Any ideas on what this stone material
is and how to remove the protective coating? Thanks for any advice
you can offer! Laura, July 19
based upon your description, your stone is probably a slate chem-lab
table. Use a paint stripper containing methyl-chloride to remove the
coating. Observe manufacture's warnings and rinse thoroughly. After
the stone dries, apply one or two coats of penetrating sealer.
Dear Laura (if you'd pronounce your name LOW-RAH, you'd be my wife!!):
I don't think that anybody can teach you over this site how to recognize
if a stone is slate or something else (I would exclude the possibility
of a manmade compound). Typically, however, many a school science
lab table were made out of soapstone. The way you describe the stone
part of the where you have removed the coating, seems to confirm that.
but, of course, it's just a (n educated) guess.
To remove the coating you will need to use a paint stripper based
on Methylene Chloride. No solvent would ever damage stone. besides,
the reason why soapstone was so popular as science lad table top is
due to the fact that it's quite impervious to harsh chemicals. Maurizio,
|Q 2239: Last year we
installed a flagstone walkway which was set in a
sand base. Recently we noticed dark stains appearing on several
random stones. We cannot identify the stain nor the reason why
this is happening? Thank you, Roseanne, July 15.
Roseanne: You do not identify the type of stone ( flag stone describes
a specific form, but not type) but aside from that, it is the nature
of all stones to begin to darken and eventually turn gray/black because
of a phenomenon called weathering, especially when directly exposed
to the elements. The staining you are seeing is probably the beginning
of this process, and is probably occurring where it is because these
1) stay a little wetter than the rest of the walk way, or 2) there
is overhanging vegetation, or 3) your dog has taken a shine to these
particular stones, or 4) a mineral streak in the stone that is oxidizing,
or 5) a combination of the above. If you find it impossible to live
with what is essentially Momma Nature's way of putting a protective
coat on the stone, then you are going to have to do it for her. First,
try some bleach on the stains and see if it removes it. If it does,
great! Then apply a sealer,, so that the little mildews and alga that
cause this to happen have a harder time getting a toe hold on the
stone. Then repeat this process oh once a year or so. Or sit back,
let nature take its course, and enjoy walking your flagstone walk
as it gently ages and settles into its new environment. JVC, USA
|Q 2191: I just closed
on my house about 3 months ago. I am very concerned for my stone
(limestone, granite and slate). I was advised that sealed granite
kitchen countertop (Atlantic black Granite honed) can be cleaned with
soap and water or a glass cleaner without ammonia. My kitchen floor
is unsealed Slate (M-1 Ebony Slate).
In my bathroom, I have honed Gasgogne blue (which only today
have I figured out to be a limestone and not a marble) it's very lovely
but we're having problems with the tile in the shower area.
About 2 months ago, we decided that we wanted to seal the bathroom
tile. We've been trying to seal it and have waited 8 weeks for it
to dry. It feels dry when touched but has about 8"-12" on all walls
with stains which look like water stain. This mark goes all the way
around the shower. We don't think that there is a leak because it
should have showed up in the floor below by now. What do you think
is the cause and remedy? Any clues? Anyway, if you could kindly sell
me some products and tell me what to do with it, I would be very grateful.
I know that you get annoyed with consumers like me who have to turn
to an expert for help, but we are at the mercy of the seller/marble
retailer. I bought my house from a developer and their subcontractor
seems quite clueless. Where I can buy the products? Thanks. Michelle,
Chicago. July 9
Dear Michelle: One thing at a time. Atlantic black hone-finished "granite"
(actually an Anorthosite, not ) can NOT be sealed with an impregnator
type sealer. It
would represent a maintenance nightmare, because all sorts of surface
soiling will show and you'll become a slave of your tops! To minimize
the problem, if the stone has been sealed already (along with the
brains of the contractor who did it!) the sealer MUST be stripped
with a Methylene Chloride-based paint stripper (anything else won't
cut it). After that, a good-quality color enhancer should be applied
to minimize the problem (if there's a sealer, the color enhancer won't
have any chance to be properly absorbed by the stone the way it should
to work). With that your countertop will turn permanently black --
though still dull, and will show less surface soiling. The cleaners
the geniuses who sealed your countertops suggested you to use are
quite wrong (what a surprise!!). Do NOT use either one of them. There
are several postings on this particular subject on this very site.
As far as your kitchen floor is concerned, I have only one comment:
I feel deeply sorry for you! You will find out why sooner than you
may be afraid of.
Unfortunately there's very little remedy. That stone does not belong
on a floor to begin with, let alone a kitchen.
Finally your bathroom limestone. How do you want it, sugar coated
or right in between your eyes? I'll make the decision for you:
Time and again I strongly advised people against using limestone in
their homes. Most of the times there are no problems, but the few
times that problems arise -- like in your case -- they're always terminal
(with no discernible solution, that is). In your case, for instance,
the problem you're reporting could be caused by a variety of factors,
i.e.: 1) an unexpected chemical reaction between the setting material
used to set the tiles and the stone makeup (nothing you can do about
it). 2) Poor installation technique (the tiles have been butt-jointed,
perhaps) and there's grout or caulk missing. And so on. Sorry about
that. (Oh, by the way, that was the sugar-coated version!)
Finally, I never get annoyed by requests like yours. I do get annoyed
at realizing -- day in and day out -- the hopeless specific ignorance
displayed by the vast majority of stone operators.
See my 'Do's & Dont's' Unfortunately they won't do you much good
at this point., Maurizio, USA
|A 2156: Please tell me
if I can re-apply new grout to good existing grout where too much
was removed during the sponging off process. This grout is in
good condition & has cured for several months. The grout has not
been sealed yet. We were hoping not to have to remove the existing
grout. Roxanne, July 3
Dear Roxanne: You can try in a small area. It usually won't work though.Maurizio,
|A 1626: I have just purchased a new
house (built 18 months ago) and have a stone
tile floor in a bathroom. A few of the tiles
were cracked and the flooring subcontractor who built the house removed
10 tiles from the floor only to find that he couldn't get a good color
match. The sample of the tile states that the name is "Silver
Travertine" (with a supplier stock number of 1205). The original
tile vendor still stocks the product; however, the currently available
stock is significantly more brown than the original and would look
terrible. How to get a dozen or so Silver Travertine tiles
that might be a better color match. Matt in Dallas, TX. March
|R1: It is impossible
for anyone to match a natural material without physical samples. I
would suggest you or your installer remove the installation and start
over to achieve a match. The other course of action is to put a sample
back in the hands of the distributor and hope that they can find someone
else who received the material at the same time. Regards, Steven,
|A 1504: I am in the process
of buying a new house. Unfortunately, I am not able to pick the color
of the marble surrounding the fireplace - I can only get white marble,
which I don't particularly like. Is there any way for me to change
the appearance of the marble once I move in? Can it be stained
or painted, etc? I don't have the money to totally replace it. Any
suggestions would be greatly appreciated. Thanks! March 8.
Dear March 8: Are you kidding?! Ciao, March 16, USA
|A 1471: I
have a river rock fireplace that needs an exterior
sealant. I am looking for the appropriate product and haven't hand
any luck. I wish to apply something that will bring out the color
of the rock (as we see when they are wet) but yet do not want
a high gloss look (preferable would be a satin sheen). I have tried
a saltillo tile sealant on some of the rocks/ it produces a satin
sheen but doesn't really retain the vivid color of the wet rock. Help!
Scot, USA. Feb 24.
Try removing the topical sealers that you have applied. Then use a
color enhancer. Once it looks the way you want it to then seal it.
regards, Steven, USA
|A 1344: I have a Green
stone counter top that was just installed. before I could
seal it my dog got on the counter and urinated on it. Can you
tell me what kind of poultice to use to extract the stain. Thank you,
Robert, Jan 17.
|R2: Dear Robert:
It's shouldn't be much of a problem. Poultice with CLEAR Hydrogen
Peroxide 30/40 volume, available at a beauty salon near you. I like
baby powder as the absorbent agent. Maurizio, USA
|R1: What kind of green stone
is it? Generally, clean with 12% hydrogen peroxide and a few drops
of ammonia. Test a scrap piece for color fastness before proceeding.
Regards Steven, USA
|A 1416: I
found that a paper towel soaked in Acetone (Nail Polish Remover)
does the job way better than poultice. again, put the paper towel
over the stain, cover the whole thing with cling wrap and tape the
sides with tape. Wait until the paper towel becomes dry 12-24 hours
- and the stain should vanish. However, now the sealants have
also been taken out. You should use any granite silicone based sealant
to seal this area. Sridhar. Feb 7.
For starters, paper towel soaked with acetone (forget the nail polish
removers: In the past few years they've been heavily reformulated)
IS a poultice.
Second, acetone only removes oily stains, period. For organic stains
you need something else, and yet something else for biological stains,
and again something else for metal stains, etc.
Finally, a poultice with acetone only take a couple of hours, tops
(after you remove the plastic cover) to dry completely. Ciao, Maurizio,
|A 1307: I have a client Whose main
concern above all is their grout to get cleaned.
The stone needs a hone and a polish as well. I think this will
do a good job as far as getting the grout cleaned. They told
me last time When, the floor was serviced with the same request,
the company ended up removing lots of the grout and putting
new in. How would you approach the job. Its a upscale clothing
store and the stone they want the work done in is the public
restrooms. I haven't see the floor yet but this is the information
that I have. What are your thoughts? Randy, Jan 8.
The newest and most innovative method of cleaning grout lines
is the Vapor Steam cleaning system. You may use nothing but
the hot penetrating power of the Vapor Cleaning System or you
can use a grout cleaning chemical in conjunction for real difficult
stains and jobs. Good luck Jerry, USA
You do not need to remove the grout, All what you need is a
grout grout cleaning product. I, personally as a stone restorer,
for the past 18 yrs, use an intensive grout cleaner with a soft
brush, It does a very good cleaning job. You may try it to see
the result. Freddy, USA
I refinish at least 100 marble floors a year (honing & polishing).
Since I actually polish the stone surface (I use a polishing
powder -- my own ), many a times most of the grout gets cleaned,
too. It much depends by the type of grout, how recessed it is
over the surface of the tiles, etc. My formal contract, however,
specifically excludes -- in bold letters and non uncertain terms
-- the cleaning of the grout as part of the job. I am stone
refinisher, not a cleaning contractor. I used to offer such
service on the side, but then I just pulled out of that business
altogether. Too many aggravations and risks, too: several times
part of the grout was coming loose and they expected me to rectify
the situation for free. Some other times, no matter what I was
doing to it, the soil was so deeply inbedded in it that it would
never come clean, or, maybe, it would not come as clean as the
areas near the walls, etc.. Conclusion: since there's no such
a thing like a sure formula on how to go about cleaning grout,
the gamble was such that they could not pay me enough In my
neck of the woods, there's a company specializing in cleaning
grout, and I believe is some sort of a franchise thing. Man,
I've seen some of their works and I can tell you that they are
darn good! When some customer insists on the cleaning of the
grout, I refer them to this company and everybody's happy. I
seldom do commercial work (I make it my business to be the highest
bidder all the time!), but if I would ever face a situation
like the one you're describing, I would hire them as a subcontractor
(and even make a little money in the process!). That's what
they do. That's all they do. Maurizio, USA
Dear Randy: This is a very common problem. I am not aware how
the stones have been laid and what is the grout width. If they
are laid "bUTT" that is with minimum grout spacing then hardly
any grout would show. but from the problem, it appears they
have left a certain gap say 3 -5 mm or more for grout. Honing
does clean up the area but if the joints have been chamfered
and are in a groove form then it is difficult to clean it by
honing. We had recently carried out a similar job wherein the
grout width was 4 mm and the stone were a mere 50 mm x 50 mm
hand tumbled. the area was LARGE. 60,000 sq. feet in all. We
did acid cleaning of the grout taking care to use very dilute
HCL (hydrochloric acid) and then using a detergent to clean
up the grout. This attempt was not very successful as the stones
were being affected by the acid. We then used high pressure
water jetting along with high pressure stem cleaner to clean
up and this did the trick. The dirt actually came out without
damaging the grout. Later we sealed the grout with a penetrating
sealer and then topped it with a water repellent silicone layer
(just the grouts). It has been six months now and the area still
looks as good as new. I hope this information comes in handy.
We also stock and sell special grout cleaning formulations.
Hi, visit www.findstone.com/articles.htm.
|A 1303: Attached are pictures
of a shower enclosure I installed in the summer of 2000.
I did not install the tile floor but did supply the tile.
The installer seemed to know what he was doing and did
some beautiful work around the house. He set the tile
in an epoxy based thin set over a rubberized membrane,
after I had installed the walls with Liquid Nails 602
over cement board. Several weeks later, still during construction,
the staining in the floor showed up. Working on the belief
it could be moisture, we let it be. Last January, while
the owner was out of the house for 2 weeks, we put a commercially
prepared poultice for oil on some of the stain. We covered
the poultice for 2 days then removed the plastic and allowed
the poultice to dry. Where we had put the poultice the
stain moved into the walls as you see it in these pictures.
The customer has been very understanding about the fact
that the original stain was due to nothing we did, however
he is upset about the stain moving up the walls
(no more than 2 inches). Do you have any ideas as to the
cause of this stain or how I can test it to find a proper
stain removal tool? Any Advice will be appreciated Thanks,
and Happy New Year George, USA, Jan 5
The photos show that all the tiles around the edge are
"stained" and the staining boundary appears to follow
the edges of the tiles, i.e. the stain does not creep
over to cover half a tile. because of these points, I
suspect firstly that the stain is caused from below and
the staining pattern is related to the laying method.
Are the unstained tiles drummy? Are the stained tiles
comparatively damp (check with moisture meter). The stain
rising up the wall suggests an active staining agent or
if it is just water, an active leak. I think your next
step is to check if the floor is damp to determine if
you are dealing with some form of leak to positively eliminate
this possibility. It would be very helpful to know if
the stain varies in intensity at all and if the colour
variation is noticeable when the floor is wet on the surface.
Regards Jim, Australia
Dear George: Now that I had the opportunity to observe
the pictures, I am more than positive about my diagnosis,
which is that you have a lot of water under those tiles.
Two other considerations come now into the surface: 1.
The selection of that particular stone, which looks like
Kashmire (granite? Yeah, right! And I am the emperor of
China, too!) for a shower stall is disgraceful, to say
the least. Unless those tiles were sealed only the Gods
know with how many massive doses of impregnator, that
stone is so absorbent that it WILL allow water going all
the way through it. 2. the floor has been installed after
the walls. This translates in a very weak "Achille Tendon"
in the overall picture. In fact, even the minimum failure
of the caulk, or grout that was applied where walls and
floor meet, will lead to an immediate access of the water
under the floor tiles, with the consequence that you can
clearly see. The whole thing is screwed-up, George, and
you can listen to all sorts of advice, but you will eventually
have to conclude yourself that there's no other remedy
if not ripping out at least the floor, let the shower
enclosure dry completely until the staining in the lower
part of the walls disappears (hopefully!), try to seal
at best the new tiles before you install them (I would
go as far as using penetrating epoxy in the back to try
to seal them, let the epoxy cure for several days, then
literally soak the tiles with a good quality impregnator),
caulk as thoroughly as possible, and keep your fingers
crossed. by the way, looking at the pictures it appears
to me that the tile setter did a good job. I can detect
a proper gap in between tiles for grouting. Further, you're
reporting he had used epoxy setting. Nothing wrong there!
It looks like you have two problems here. 1st the product
called Sahara beige/Ghibli is a very absorptive stone.
So the stone has absorbed the moisture and possibly what
ever else that is behind it that could bleed. Quite probably
it absorbed some of the poultice. Second, Maurizio told
you that the deposit at the joints is efflorescence. I
advise removing the the stone and reinstall waterproofing
because the efflorescence seems to be coming up rather
than looking like a hard water deposit. This stone is
really not appropriate for a shower and you must institute
a good impregnating maintenance program for the consumer
to follow and you to supervise. You may have a problem
with liquid nail bleeding through. There are many reports
that it can happen. I tell you because you sold them a
stone that was unsuitable for a shower and installed the
cement board with liquid nail. I am curious about the
pan though, I wonder if your installer used a full spread
method of installing the pan tiles. If he did I question
whether or not he used epoxy. This is your problem whether
it was by ignorance or negligence. I am happy that you
cared enough to go this far. best regards, Steven, USA
I've used Liquid Nails 602 on numerous installations never
had a problem with it bleeding through the stone. George.
Hi George, I know. We did too for a few years. The manufacturers
of liquid nail started excluding their products from areas
with natural stone because many of them are too absorptive.
Liquid nail in a direct wet area is something I have never
done because we never found it to work. So what I will
publicly say is this; the liquid nail should not have
been my focus at all. I am sorry about it being construed
as if it were. The most salient issue is the Ghibli and
it being in a wet area. The staining problem you see is
because of the sheer absorptive nature of the product.
The probable efflorescence is why I mentioned liquid nail.
If this is efflorescence, then water is getting to the
core of the installation. This means that possible cementious
nature of the backerboard is leeching. If this is the
case then you have to stop water from getting into the
substrate. How do you do this? Ghibli is tough to seal
for a countertop and I consider it improbable to be able
to stay ahead of the curve in a shower. Improbable because
I have never taken the chance. If the installation was
done with full spread epoxy adhesive, then efflorescence
should not be occurring. That is why I question the adhesive.
As an advisor on this forum, I only try and help all parties
affected. I still appreciate the fact you are working
on this. It speaks well for you. Regards Steven, USA
|A 1279: Have water stains
around the faucets in my bathroom. Seems to be slightly chalky.
How to remove and seal? Cecil, USA, Dec 23.
|R1: Dear Cecil: Try with a brand new razor blade. If the mineral
has already dug into the stone surface, however, (pitting) there's
nothing you can do, short of hiring a professional stone refinisher.
No sealer will ever help you for that particular problem. Maurizio,
|A 1230: I have
a natural stone hearth and wall section for a wood stove. The stone
is as if split in two with the split surface facing the room. This
stone is from the Adirondack Mountains area & contains a lot of
garnet. The stone is clean but shows no depth to the beautiful colors.
Can you suggest a specific product to give me
the color depth? Jack, Nov 30
|R3: You will need to contact a marble or stone restoration
person. Atkin, USA,
|R2: Make the stone wet. If you like this look, then you can
use a color enhancer and then impregnate the stone with a good quality
stone impregnator. Quite possibly, you could try having someone (with
proven experience) to come out and polish the stone for you. Messy
and expensive. best of luck, Steven, USA
|R1: Dear Jack: There are specific products called "color enhancers".
You may want to check into the company listings in this site to find
a manufacturer that makes one of them., Maurizio, USA
I've laid Niagara marble for flooring
of my house. After polishing, fine hair line cracks radiating in
all possible directions just like a tree are seen. What could
be the causes? Soudhamini, USA, Sept 24.
|R2: The dimensional stability of the mortar / adhesive
used to lay the stones may be suspect. The fact the cracks radiate
in all directions suggest that the stresses are also in all directions. More
information is really needed to solve this one such as how were the
tiles adhered, what were they laid on, how thick are the tiles, have
the tiles undergone any other treatment or exposure such as flooding,
how long have they been down for. Regards, Jim, Australia,
Wrong sub-flooring, or poor installation work. Ciao, Maurizio, USA,
A 1057: I'm tired of replacing and/or cleaning my
carpet which was used to cover the natural stone on the stairs of our home.
After removing the carpet however, the stone is in bad shape. There
are holes from the nails, brown discoloration which has seeped in from the
glue and other spots from the carpet which has been in place for many years.
How can I clean and refurbish these natural stone stairs. The
home was built in the early 1930s and it is beige in color. Carol, USA,
R1: You don't mention
the kind of stone that was used, and the cleaning treatments do vary depending
on the stone. Please stay away from any cleaning solutions that are
acid based. If the stone is limestone, or marble, acid will have a very
negative effect on the stone. If the stains are surface stains, the
stone can probably be refinished (i.e. sanded). Sometimes bleach will
help. Sanding will also help with the nail holes, although some will probably
need to be filled with a stone patch. Stains that penetrate the stone
can often be lifted by using a poultice. The composition again varies
depending on the stain. Please check with your local tile store, or
with a local fabricator to determine what the best course of action should
be. JVC, USA.
|Comments? Complaints? Compliments?
The views expressed in this section are not of FindStone.
just spent about ten minutes looking at your site, but from what I
did see I am very impressed. It looks very helpful and user friendly
I will use your site for various things in the future, Thank you for
this resource. Randy, CLEANING CO. , FL, USA.