Sealing Marble Shower Tile & Grout

Carrara Marble Shower

Carrara Marble Shower


I just installed new marble tile in my bathroom on the shower walls and floor.

Should I seal the marble tile and grout?

What is the best sealer for a marble shower?


Whether or not to seal a marble shower has arguments on both sides.

Some claim it's a must do while others say sealing showers doesn't really serve much purpose and may cause a problem in some cases.

Let's look at the reasons for and against and our take on it...

Do Marble Showers Need Sealing?

You may read or hear that ALL stone MUST be sealed no matter what... but that is just not true.

It depends on the stone, the location and intended use of the stone installation. For instance sealing marble kitchen countertops is usually a good idea.

Kitchens get way more traffic and abuse than bathrooms do.

On the other hand, some marbles, granites and other stones are naturally dense, stain-resistant and don't need sealing.

Problems can occur from sealing a shower. As a general rule... you don't want to apply a sealer to marble or natural stone in a shower (with one exception discussed below) or other wet environments because you run into situations where the sealer may trap water in the tile causing many problems including degradation of the stone.

Applying a sealer is done to reduce the risk of stains in marble or stone. This is very helpful in areas like the kitchen, dining room, or high-use floors or countertops in a bathroom.

The risk of staining in marble showers is near zero unless you regularly toss a salad or drink some wine in there!

Think about it... you use very few products in the shower, and when in use water is constantly washing them down the drain.

You'd have to leave a leaky bottle of something sitting on the marble tile for it to ever have a chance of staining.

Plus, marble actually is not very porous and does not stain easy.

Marble will etch easy and people always confuse etching (whitish dull spots from chemical corrosion) with staining, but these are two different marble maintenance issues.

And even if it did stain, marble stains can be removed in nearly every case.

Some people mistakenly believe that the reason to seal shower tile is to prevent the shower water from absorbing. No... also not the case (with one exception... see below).

A little water may absorb into the marble or travertine tile while showering, but it quickly evaporates and does not cause any problems. This is normal.

You don't gain any real benefit by applying a sealer since your stain risk in a marble shower is minimal. BUT... you do risk creating unwanted problems by sealing a stone in a wet environment.

In truth, the sealer itself won't "cause" a problem out of nothing, so don't worry if you've already sealed your marble shower.

However, in a case where water gets behind the tiles of a sealed shower (from cracks or voids in grout or caulk), it will block evaporation potentially making damage a lot worse.

Exception to the Rule: White Marble Showers

White marble showers are an exception to the general rule to avoid applying a sealer in wet environments.

White marble like Carrara marble, Calacatta marble and others can contain small iron deposits. Water can oxidize these deposits, which may lead to a rust stain that is difficult to remove.

This is most often a problem on floors after a flood or from a plumbing leak. Meaning the tiles and the iron deposits must be exposed to water over an extended period of time or from a continuous source.

In a shower, this could sometimes occur from water behind the tiles and not simply from water absorbed while showering.

First, marble is not that absorbent and water would have to be on the surface for quite a long time (maybe 15-30 minutes or more) before it even starts to absorb.

Honed marble tile will absorb a bit more readily, but shiny polished marble tile has a very low rate of absorption and water may not absorb
at all.

Also, since tiles are never really submerged in water in a shower, it is typically absorbed only into the surface (if at all), doesn't saturate the tile and dries quickly.

Thus, any iron deposits within the tiles (unless near the surface) are not exposed to water long enough to oxidize or rust and stains rarely occur.

Floors, benches and shelves are at greater risk for rust stains in white marble showers since water is left standing on these surfaces allowing more time to absorb and potentially oxidize embedded iron deposits.

Better safe than sorry; so, sealing white or Carrara marble shower tiles to help prevent iron oxidation is a good idea, although polished marble often can't be sealed as explained below.

What is the Best Sealer for a Marble Shower?

If you do decide to sealer your shower or if y ou have a white marble shower, then SenGuard Permanent Stone Sealer is the best sealer for the job. It can be applied to both the tile and grout.

Or applying a standard quality impregnating sealer will work too but you just have to reapply it periodically.

Why is Senguard the best?

First, Senguard forms permanent bonds with the stone which means you only have to seal the marble one time. No periodic re-sealing is necessary as is required with all other sealers.

Also, its advanced technology allows for better penetration (particularly on dense, low-absorbency stones), more thorough coverage for enhanced protection against both oil and water-based stains and it's super-easy to apply.

Addition Marble Shower Sealing Tips

Poorly installed shower tile is a problem. You may have gaps, cracks or voids in the grout letting water flow behind the tiles where it gets trapped. But sealing won't help a lick in this instance... in fact, it would make it worse as noted above.

You can spot this problem as the shower tiles will start to turn gray or darker. Usually, the floor tiles are most affected but you may notice the wall tiles that touch the floor become darker as well.

What happens is the water behind the tile absorbs into the tile and darkens it. White tile like Carrara marble will look gray.

Often you'll see that half of the wall tile is gray or darker. This occurs as the water from the floor rises up inside the wall tile. Again, this is from water trapped behind the tiles.

If you decide you'd like to apply a sealer in the shower, then first perform the water test for sealing to determine if your marble could even absorb a sealer.

Sealers must absorb into the stone to work. Dense, low-absorbency stones (like polished marble) typically do not need sealing and often "cannot" be sealed because the sealer won't absorb.

Obviously, it would be absolutely useless to attempt to apply a sealer to a stone that can't absorb it and doesn't need a sealer.

Applying "just to be safe" doesn't work here. You're only looking for trouble. The result is wasted time, effort and money and a streaky sealer residue on the stone.

Waiting 2-3 weeks after shower installation is necessary before applying a sealer to allow the stone, grout and all installation materials to dry out completely or you'll trap water in the stone.

Sealing the bathroom floor is not a bad idea though. The "general rule" discussed above still applies, however, floors, benches, shelves or anywhere you may store products are at the highest risk in the shower but still pretty low-risk.

I suggest using one of these recommended marble & granite sealers.

Again, SenGuard is the best available.... head and shoulders above every other on the market. We really like this product and highly recommend it.

No need to polish marble prior to sealing unless you are repairing etch marks. Better to repair first, but you can always re-apply a sealer to any spots where etch marks were repaired.

Sweep and clean the floor tile prior to sealing. Sealers don't form a topical coating, so it won't trap dust or dirt, but you want a surface free of gunk or debris to ensure easy absorption for the sealer.

Comments for Sealing Marble Shower Tile & Grout

Click here to add your own comments

Sealing White Dolomite Polished Marble
by: Anonymous

Hi, Great article! Thanks for all the valuable information for a marble novice.

We're currently installing white Dolomite polished marble for our shower walls and honed Carrara marble on the shower floor.

What would be the best method to apply the sealer on both areas? Any advice would be greatly appreciated. Thanks.

==== Countertop Specialty comment:

For the floor... pour on a little sealer and spread around with a paint brush to create a thin film over the entire surface.

For the walls... it's a bit more difficult, but walls are less susceptible to stains and water penetration. Use a spray bottle to apply the sealer also trying to create a thin film for the stone to absorb.

Spray on and then use the paint brush to spread around if needed.

Of course, you need to let the sealer absorb for 3-5 minutes, but then wipe all excess off and buff dry completely. Don't let sealer dry on the surface or you may get streaks.

Steam shower sealing
by: Craig

So, I have a steam shower and tile with 12 x 24 Malan gray marble honed tile and also 4 x 6 white Carrera honed and was wondering should I seal the tile or not seal the tile?

==== Countertop Specialty comment:

Well, a steam shower is harder on the tiles and will wear on the surface more than a standard shower.

Typically, you do want to seal Carrara marble and any white marble as iron deposits embedded in white marble can oxidize and cause rust stains.

So, I'd recommend to apply a sealer but you should also test the stone for absorption every year or two to see if you need to seal again.

Again, steam just wears more on the stone if it is heavily used and may require more frequent sealing. But just test to determine when or if it does.

Beige tile around a shower
by: Anonymous

I have a one piece shower/tub unit and am in the process of installing Queen beige amalfi marble subway tiles on the walls around it. The tiles cover roughly two feet of wall between the top of the shower and the ceiling as well as the surrounding walls to the floor.

The guy at The Tile Shop where we purchased the tile said we should seal the tiles before and after grouting. However I am questioning whether this is the best move after reading this article.

I’m completing the work myself on weekends, and as this is the only shower in my house it’s not possible to let it totally dry out for 2-3 weeks after installation.

I have not grouted yet but have the tiles covered to protect them from any little bit of potential splashing water, and hopefully from condensation from any shower steam (we vent the room when we have to shower).

In my situation, would it be best not to seal the tiles at all? The point of tiling was to protect the walls from shower steam etc but I’m concerned that if I seal them as recommended at the store I may cause a problem. Thanks!

==== Countertop Specialty comment:

Sealing tiles prior to installation or prior to grouting is typically only done when the grout color is a lot darker than the tile color.

The reason is to prevent the grout color from bleeding into the tile creating a dark "picture frame" around the tile edges.

But if you cannot let the shower dry out before sealing, then yes consider not sealing it or seal all tiles prior to grouting. Of course, that leaves your grout unsealed.

Usually, sealing a shower doesn't cause a problem. It's just not really necessary in most cases and can potentially lead to a greater problem.

More on Carrara Marble Shower
by: Donna

The installer said he would come by and have to "check a few things" to determine what’s wrong but insists the pitch he installed was on point.

He cannot return to inspect for a few weeks, will mold become a problem if we wait this long?

By the way, I did the water test you suggested and it’s fine everywhere else in the bathroom except the shower area where it gets absorbed.

If there was a way I could send you photos please let me know. Donna

==== Countertop Specialty comment:

If you don't use the shower and let it dry out then the mold will die off.

Note that we can only speculate at possible problems based on the info we are presented. The installation may be fine and something else is at work.

However, the difference in the water test between the shower floor and all the other marble is definitely a clue that your installer should consider when trying to figure this out.

You can send us photos via our Contact or Support forms. Click on this link, then on the next page click Contact Us at the top or the green Support tab on the right.

Honed Mosaic Carrara Thassos Marble Shower Sealing Problem
by: Donna

We just installed a honed mosaic carrera marble tile on our shower floors, and our entire master bath flooring. We ripped up the old shower floor and constructed the new shower with a curbless entry.

We installed a tile in linear drain and it’s gorgeous.

The installer instructed us to use 511 impregnate sealer on the floor prior to use.

We applied two coats on the shower floor area and one on the remaining floors which is also the same material.

After the 72 hour time frame, we used our brand new spa shower. A day later the shower floor was four shades darker than the floors around it.

Stunned and saddened as we noticed they didn’t go back to their "normal" dry color.

We stopped using the shower and waited two weeks for it to return to its normal state.

We were instructed by our tile installer to go over that area with two more coats of 511, which we did. We used the shower for the first time again yesterday, and nothing has changed.

The honed marble is dark again, and it doesn’t return to its normal shade.

We don’t know what to do except believe this is the nature of the stone?

The installer used shouter water proofing system and white thinset. Any suggestions would be appreciated.

==== Countertop Specialty comment:

Sounds like water is getting under the tiles. With a new install you shouldn't have cracks in the grout but there may be a problem with the plumbing, shower pan, or drain that is causing water to accumulate under the tiles.

Water can absorb into stone and then evaporate without issue. It will darken the stone, but then disappear once evaporated.

However, marble really isn't that porous to begin with and if it was properly sealed no water should be absorbing.

Two coats of 511 should have sealed it just fine.

The key seems that there was some delay in the stone darkening after use. If water was absorbing from the surface you'd see that within 30 minutes of use.

If it took until the next day to see it darken, then it is likely water is absorbing through the tile from underneath.

Spill some water on the bathroom floor outside the shower and see what happens. My guess is that it will take forever to absorb and darken (if it does at all). It is does darken it will quickly disappear (within a a few hours or less) as the water evaporates.

Try the same (let a puddle of water absorb) inside the shower for comparison. But the shower floor must be completely dry and back to normal color first. And don't let any water down the drain as this may be the point where water is getting under the tile.

Time how long it takes to darken the stone in both locations and note any differences to give you clues to the nature and source of the problem.

If the water test results are the same for both locations (i.e. takes the same time to absorb and lighten again) then the problem is likely water under the shower tiles.

Hopefully, it is not this problem because would likely have to rip out and reinstall it.

Good article
by: Anonymous

I’m preparing to have marble installed in my bathroom. After reading tons of articles about to seal or not to seal marble, this article explains best about what to do. Thank you for your information.

China Marble
by: Anonymous

I purchased Bianco Orion Polished Marble Tile for shower walls. I was told to seal prior to install. I have done that (511 porous plus), its not on the walls yet.

I was told to seal all sides of the marble.

Now I have read somewhere else the grout will not adhere to the sides of the tile. Have you ever seen where this would be an issue?

Do you have any idea if this type of marble has rust issues?

Also I have noticed the marble is from CHINA, do you know anything about marble from china? I never knew there was such a thing, but that is what I have and the cost was 50% less.

==== Countertop Specialty comment:

Sealing the tile prior to install and grouting is fine. Only really necessary if you are using a dark grout that could bleed into the stone and cause some darkening of the edges.

But the grout will still adhere just fine. No problem.

It is a white marble and many white marbles do have iron deposits embedded and can, therefore, develop rust stains if water absorbs and oxidizes the iron.

Marble from China is fine. Many natural stones come from China.

Black granite is the only one with any real issues as it can sometimes be "doctored" or dyed to make more black. This causes problems with etching.

Carrera marble tile on shower walls.
by: Anonymous

I have read your wonderful post and comments but want to clarify one thing... I only have beveled Carrara white marble tile on the walls to the top of my tub and ceiling.

I have good ventilation in the bathroom. Since I don't have any surface that water can stay, I am thinking of not sealing.

But what about the grout? Should I still use your product for grout?

Does grout dry and crack with age? Or should I leave it because if it gets wet then it can evaporate.

I don't mind iron deposits. It will go with my rustic bathroom. Thank you so much.

==== Countertop Specialty comment:

If you think sealing the marble isn't needed, then it isn't needed for the grout either. Sealing is done to prevent substances that could stain from absorbing into the stone or grout.

The iron deposits in white marble like Carrara marble can lead to large and irregular yellow-orange stains. Generally, not pretty.

This is the reason to apply a sealer to white marble in showers or around tubs where the marble will be regularly exposed to water.

Of course, if just a tub surround and the there is no shower so the walls will not be exposed to water much, then your risk of rust staining is much less.

Help, huge smears!
by: Anonymous

Great article, I have questions.. we had a wetroom both walls and floor tiles with beautiful marble.

The tilers were very particular and did s lovely job. But between tiling and grouting and then sealing the tilers told me to stay out of it until it’s sealed as I could stain it.

Hence I did as I was told, now since it has been ‘sealed ‘ and now fully operational I’m not happy with the finish.

In certain points where the light shines I can see huge smears the whole thing just looks dirty. I suspect this is because the sealant was applied over dust and dirt as I can’t no matter what I do get these smears off.

I know I’m not aloud to use abrasive cleaners so what do I do, does the sealant need to be stripped off and cleaned and start again or what do I do, please help.

==== Countertop Specialty comment:

It could be either grout haze (film of grout stuck to the tile) not properly removed or haze from sealer residue due to incorrect sealer application.

Both can look similar (chalky, dull) but grout haze will usually have a slight texture.

To remove grout haze use the Hard Water and Soap Film Remover which will remove the grout but is totally safe for use on marble.

Also, use this cleaner as your regular shower cleaner to eliminate film buildup that occurs in every shower.

To remove sealer haze, you'll need to scrub with acetone, which won't harm the marble. If acetone doesn't work, then you'll have to use a more potent solvent like methylene chloride (found in paint strippers). Also won't harm marble.

Sealing after rust stain removal?
by: Anonymous

I have polished carrera shower walls. Installed professionally about 1 yr ago.

After about 6 months, I noticed brown patches showing up in the carrera, which is definitely oxidizing iron deposits.

I am on vacation now, so letting the marble dry out for about 10 days.

Then I plan to remove rust stains with a poultice of Iron Out and baby powder. Fix any etching with polish powder.

My question is - should I seal with a permanent product (SenGuard)? I'm worried the rust patches might come back and then I wouldn't be able to remove them with a poultice if I've sealed with SenGuard.

I'm not sure how the water exposure occurred in the first place. I've inspected the grout and I've found only a few very tiny hairline cracks or tiny pin holes, but these aren't even necessarily near the tiles that have the brown patches.

I think the stone is somewhat abosorbent because I've noticed dark gray vertical lines forming when condensation droplets runs down the walls during a shower. I can't do the water drop test, though, because the stone is only on vertical surfaces.

What is meant by "faulty installation?" I've installed some tile myself before, so I know the main process. This marble was installed by professionals.

Should I seal after removing rust stains? And how do I keep them from coming back?


==== Countertop Specialty comment:

Yes, you should apply a stone sealer after removing the rust stains and fixing any etching.

SenGuard is your best option. Best protection and permanent bonds.

The rust stains can happen with repeated cycles of slight water absorption into the face of the tile. Problem is worse with cracks in grout, etc.

Showers don't typically require sealing, except white marble for exactly this reason. Grout can be perfect and can still get rust stains.

It won't happen in every white marble or Carrara marble shower, but not worth the risk. Seal it for sure.

The sealer will not prevent you from removing any future stains. The chance of additional rust stains after applying Senguard should be minimal.

The primary factor post-sealing would be the integrity of the grout. Make sure it's always in good shape and shouldn't have problems in the future.

Nemo carrara mosaic darker in "wet" areas
by: Anonymous

Hi there, we just had Nemo Ruscello tiles (small mosaic in honed carrara marble) installed in our shower floor and one wall. We asked the contractor to seal them as we were told to do so.

Now whenever we take a shower in it, the area where the water hit stays and looks wet and darker. Not the entire floor though, just the area where the water hit directly, both on the floor and the wall.

Any suggestion on how to deal with this? Thank you!

==== Countertop Specialty comment:

Probably the tile was not sealed or not sealed well enough and water is absorbing creating a dark spot that goes away when it evaporates.

Typically, this is not a problem, however, Carrara marble can contain iron deposits that can rust with repeated water exposure.

So, you need to make sure the tile is sealed properly.

Carrara Marble dull after grouting
by: Anonymous

Do you polish the marble before sealing. After grouting the tile looks dull.

==== Countertop Specialty comment:

If the tile is dull after grouting, then it is probably due to grout haze on the face of the tiles.

This must be removed, but careful what you use. Most grout haze removers will etch marble.

This Hard Water Remover for marble will remove the haze safely.

Once the haze is removed, you can apply the sealer.

And by the way... the Hard Water Remover is also the best cleaner to use as your "regular" shower cleaner.

Carrara marble turning gray
by: AnonymousCarole

I just had the basket weave honed Carrara marble installed on the shower and entire master bathroom floor.

I haven't even started using the shower or bathroom since it is still being renovated.

I already have noticed the marble turning dark gray just from them getting water on the tile from a sponge or spilling water from a bucket.

In some of the areas it take days to lighten back up. I'm really worried to see what will happen to the shower floor once I actually take a shower.

I'm concerned about sealing the floor in the shower area since it can cause evaporation problems but I don't want to risk getting iron oxidation of the floor.

What do you recommend I do.

==== Countertop Specialty comment:

In general, natural stone tile does not need sealing in the shower since the risk of staining is very low.

The one exception is white marble like Carrara marble precisely because of the iron deposits within the marble and potential for rust staining.

You must apply a sealer to prevent this. Applying a sealer to shower tiles is only a problem when water is getting behind the tiles. This can happen with an improper installation, or more commonly, when there are cracks or voids in the grout.

When the shower tiles and grout are in good condition the sealer will not cause any problems. It will simply keep water from absorbing to prevent oxidation of the iron deposits within white marble.

The iron deposit problem is not an issue with any other marble or natural stone color.

Marble tile will darken or turn gray when water is absorbed. This is normal. However, it should not take days for the water to evaporate and the spot to disappear.

If this is the case on newly installed marble shower tile, then I consider that the installation was not done correctly and water is getting behind the tiles.

Or it could be that the shower / bathroom does not have sufficient ventilation / air flow to promote evaporation.

Cream Beige Carrara Polished Marble
by: James

Howdy. Excellent article. If I may ask, is it white....and only white Carrara marble you recommend sealing, or would a "cream / beige" Carrara fall into the same category.

Our cream / beige does have hints of off whites intermixed. Thanks in advance.

==== Countertop Specialty comment:

"Carrara" marble can be different shades of white (some lighter, some more grayish, or slight hint of yellow), but usually is not anywhere close to "beige".

Understand that "Carrara" references a specific marble quarried from Carrara, Italy. It is a white marble (with grayish tones and blue / gray veining).

There are many cream / beige-colored marbles, but these are not "Carrara" marble.

So yes, it is only the white marbles (like Carrara, Calacatta) that contain iron deposits and should be sealed when installed in a shower.

Of course, if you like you can apply a sealer to your marble shower tile. It isn't a high-risk area for stains and is generally unnecessary, but won't cause any problems unless water gets behind the tiles.

Water getting behind the tiles will only occur when there are cracks or broken grout lines. In rare cases, due to a poor tile installation.

So, if your shower is in good condition, the sealer won't cause any issue. Just really not needed except for white marble.

Grout separation from natural stone shower
by: Anonymous

Thank you for explaining how to care for your white, off white in our case, stone.

Unfortunately, our shower is beyond the prevention stage, and has been exposed to water for over a year, and has turned orange-the grout being much worse than the stone.

A larger concern is the grout connecting the floor and the wall has pulled away from the wall, and water continues to get behind it.

I do not know how to proceed with preparing this area before moving on to the sealing.

I've considered using a chisel or dermal tool to remove the grout, or a portion of it, and then replace it, but am afraid I will make matters worse, or create a huge problem.

I am looking for an educated suggestion on how I should move forward with this project.

=== Countertop Specialty comment:

The only way to move forward with this problem is to remove the old grout. This shouldn't be a problem. You run very little risk of damaging the marble.

However, as you stated the marble has turned orange it may not be worth saving.

The orange coloration is rust staining.

White marble contains iron deposits. When the tile gets saturated these iron deposits oxidize and the rusty water moves to the surface and evaporates leaving the orange rust stain.

This type of rust stain is permanent. It is too deep in the tile to remove.

It sounds like you let this go far too long and, honestly, I'd seriously consider ripping it all out and installing a new tile shower.

But if you want to go with repairing this one, then you need to stop using it for a week or two to let it dry out completely. Water is likely trapped under the tiles and this needs time to evaporate.

Given your description of the current condition, I'm surprised you don't also have mildew everywhere.

Anyway... let the shower totally dry out. Then remove all the grout using a Dremel, chisel, or scraper or however seems effective. Then re-grout.

Wait another 2 - 3 weeks to allow the grout to dry and any remaining moisture to evaporate and then apply a good sealer.

Sealing honed marble shower floor against etching
by: Floyd

We have a newly installed hex mosaic honed carrara marble shower floor.

The shower went unused for a good 3-4 weeks from install before we started using it. We unknowingly used some cleaners that produced a few etch marks before reading up on the proper care of marble.

Our tile guy said we could use any kind of cleaner, bad advice. Anyway, I bought some etch remover and the proper cleaners for stone and I also want to seal the marble to prevent future etching or iron stains because the stone is soft and more absorbent than polished marble.

My question is, how long should I let the floor dry after showering or cleaning before I apply the sealer?

==== Countertop Specialty comment:

Since you let the tile and grout dry out real well for 3-4 weeks after install you won't have to wait so long this time.

That is assuming the installation was done well, grout is all tight with no cracks or voids that could have allowed water to get under the tiles. Most likely everything is fine, but just letting you know the variables.

I'd let the shower dry for a week prior to applying the sealer.

But note.... a sealer will prevent stains and water absorption that could lead to rust stains from the embedded iron deposits found in Carrara marble.... however, sealers won't prevent etching.

Etching is physical damage to the marble. It's like a burn. So, expecting a sealer to protect against this is like expecting car wax to prevent a scratch in the paint from a key or some other hard object.

Etching in a shower 99% of the time is due to use of the wrong harsh cleaners (which is most common cleaners) to clean the marble.

You should use the Soap Film / Hard Water cleaner as your regular shower cleaner.

This product is specially formulated for use on marble, travertine and all natural stone without any damage or etching. And it is super-effective cleaning the films that are the biggest problem in showers.

So, fix the etch marks, seal it (I recommend SenGuard Sealer) and then clean it with the right product and you won't have any more problems.

Sealing To Prevent Rust Stains White Marble Shower
by: Anonymous

I have a white marble shower saddle that was sealed. Then they installed the shower door with a stainless steel screw.

The screw hole rusted and we have to replace the saddle. We don't want this to happen again.

Should we be sealing after the shower door is installed? It seems like water will always get down the screw hole.

==== Countertop Specialty comment:

Yes, this could be a recurring problem unless you find a way to seal off the screw hole from the marble. I know stainless steel is not supposed to rust (in theory) but it still does under certain conditions.

You should be sealing inside the screw hole, but this won't completely stop a rust stain from developing.

I'm sure the screw hole is collecting water that just sits there oxidizing the metal. The rusty water then eventually absorbs into the marble.

Note that a sealer cannot absolutely prevent absorption. Sealers dramatically slow down absorption, but don't completely prevent it.

If the water sits long enough the marble will absorb it even when sealed.

I think the key here is that all parts used to install the door must be 100% stainless steel (not just plated), but then if possible, caulk around the screw hole to prevent water collecting and remaining around the screw.

even water can't escape gravity
by: Anonymous

The wall grout where the water bounces off of the person showering will soak up enough water to be pulled into the edge of the tile by gravity.

A simple test would be to towel off those areas after showering. If the water didn't penetrate the grout then it should not remain dark from the water, if it remains dark then the water has penetrated the surface of the grout and gravity will take it from there.

=== Countertop Specialty comment:

True, grout is porous and will absorb some water. However, it is not a sponge and the amount actually absorbed (especially on a wall) is minimal, at the surface only, and will evaporate before it does any real damage.

Gravity may take it into the stone or the stone itself may absorb some water when showering, but again... it's only at the surface and so minimal that it will quickly evaporate without leaving a trace. And this repeated process can go on for years and years without any issue, damage or staining.

It's only when significant amounts of water get behind the tiles and grout that staining and damage occur. And significant amounts of water don't enter unless via cracks and voids or poor installation... not from surface absorption.

Now if the shower had really bad ventilation and never dried out, then I'd agree that even the minimal surface absorption could become a problem as more water is added with each use of the shower. Certainly, you'd have a mold / mildew issue but could also get staining and other damage to the tile and grout from the constant water exposure.

Sealing statuary white marble shower tile
by: Anonymous

Thanks for the article. It says polished marble does not absorb much so sealing in the shower is not necessary. Then there was a comment from the site recommending sealing a polished Carrara marble in response to another person's question.

Should you seal polished statuary marble inside a shower? Or floor as well? Thanks so much!

==== Countertop Specialty comment:

You may have missed the section about "exceptions" to sealing marble shower tile. White marble is the exception since it can contain iron deposits that can cause rust stains with repeated exposure to water.

So, yes.... you should seal statuary white marble shower tile even when polished.

It is true that polished marble can be nearly non-absorbent so the risk of rust stains on a polished (vs. honed) marble is lower, but white marble in a shower is the one case where it is beneficial to apply a sealer to a low-absorbency stone.

Rust stains from embedded iron deposits are basically permanent, so you want to do everything possible to avoid them. Just be sure to apply the sealer correctly and do not allow it to dry, wipe off all excess after absorbing and then wipe the marble completely dry and buff out any streaks.

You didn't mention the grout
by: TS

A customer of mine pointed this article/blog out to me, I am a stone restoration professional with 10 years in business.
I agree with most of what has been said in this article, and it it very refreshing to see that there is some "Real" advice out there as far as sealing natural stones goes.

The only thing not mentioned was that the grout is very porous and will soak up water even on the walls. Remembering that the edges of the tiles that the grout is up against is rough cut and not finished like the face of the tile, this makes it tremendously more porous, thus the need for a sealer to guard against water intrusion through the sides of the stone (like was mentioned with the grout color penetrating through the sides).

I have seen marble showers where the water soaked in through the sides and down to the lower tile and a half, making the appearance of fish bowl waves.

My only point is that the grout will be porous no matter what the tile is.

Very good article, just my two cents. I can tell by the products that you recommend for maintenance on your site that you are very knowledgeable about how to care for your stone, keep up the good work!

==== Countertop Specialty comment:

Thanks for your input! Yes, grout is porous, although, when properly installed water absorption is not an issue.

The amount of water absorbed during a shower is minimal and will quickly evaporate.

When water does cause damage it is nearly always because of cracks, voids or faults in the grout (or from poorly installed tile / grout) allowing a much higher volume of water to enter and get behind the tile. This is especially true on walls where water never has a chance to pool.

When water gets behind shower tiles it will not evaporate quickly and will start to cause damage or consistent mold issues, etc.

And when the tile and grout have been sealed the evaporation of water behind the tiles is slowed even more. Even though modern stone sealers allow the stone to breath, it is not the same as an unsealed tile and water behind a tile is effectively trapped.

For the above reasons, it is unwise and unnecessary in most cases to seal stone or grout in a wet environment (except for white marble tile showers).

But also, it is very important to routinely inspect grout lines for cracks and voids. Allow the shower to dry out thoroughly and make needed repairs in order to maintain the long-term integrity of your shower tile.

Cream Colored Travertine Shower Walls and Bench
by: Mike

Hi! Thanks for your valuable info! Should we leave our cream colored travertine subway size tile on our shower walls and bench in the shower as is or follow the same rules as the white marble? Thanks!

==== Countertop Specialty comment:

Travertine shower walls are at virtually zero risk for staining and the "white marble" issue doesn't apply so no reason to seal the walls.

The bench you may want to seal only because water and other products left over from showering or from leaky bottles set on the bench, etc., could cause a stain.

Still not too big a risk on the bench, but probably the most likely place in your shower (along with shelves) to get a stain and easy to seal it.

Enhanced sealer on carrara floor
by: KP

The contractor just laid a carrara floor in our master bath & used an enhanced sealer. We now see smudges & marks everywhere. Does anyone know what this is & why it happened?

==== Countertop Specialty comment:

Well, it depends on what these smudges and marks look like, but it could be due to sealer residue on the surface. It may be that the sealer did not absorb well and/or residue dried on the surface.

Try cleaning with acetone in a small area and see if it clears it up. Acetone won't harm the Carrara marble, but it will hopefully remove any residue.

Greecian White Subway tile for shower
by: Marsha

I ordered 115 pieces of Greecian White Marble Subway tile, Premium Mosaics, for a walk in shower that is going to be built.

I was told at Home Depot, where I ordered it, that I would need to seal the tiles "before" grouting them and then "after" grouting. This is due to absorbency issues with marble tiles.

Is this true....because the tile guy at Lowe's said to not do that to their tile that I ordered for the back wall of the shower.

Of course their tile is mixed with white and tans. The reason I am asking is I don't want to do unnecessary sealing. I read your blog about white tile needing sealing but saw no mention of double sealing. Don't want to make a big mistake!!

==== Countertop Specialty comment:

Sealing marble tile or any stone tile prior to installation is sometimes recommended as a way to make clean-up after grouting easier, but this reason is very debatable.

The real reason you might want to seal marble shower tiles prior to grouting is if the grout is a darker color than the marble.

If so, the moisture and dye / color from the grout can absorb into the marble tiles creating a stain all around the edges which looks like a picture frame.

Such stains run through the full thickness of the tile, so it will be permanent.

However, if you are using a light-colored grout basically the same color as the tile, then you shouldn't have any problems of this sort and can wait to apply a sealer to the entire finished shower.

And yes, you do want to apply a sealer to white marble in the shower. Typically, shower tiles do not need sealing. No real risk of staining.

However, white marble contains iron deposits that can cause rust stains with repeated water exposure, so white marble shower tile is the one exception where you do want to apply a sealer.

I recommend using Senguard Sealer for Marble & Granite. It's the most advanced and permanent.

sealing carrara marble showers
by: Anonymous

Thank you for this excellent advice. I find it very enlightening as I was about to seal my new marble shower.

Now I know to wait for 2-3 weeks to seal only the shelves and bench where products and water may lie for a time.

Still Confused
by: Todd

We've just installed white arabescato marble in a bathroom. It's on the floor, around the toilet, vanity counter, and shower floor walls and bench.

I've looked at multiple sites and am still confused on whether I need to seal the Marble and even then if it needs to be an impregnate seal. Can you shed some light on this? Thanks.

==== Countertop Specialty comment:

You should apply an impregnating sealer to the marble in the shower at least.

Now, the proper thing to do first is perform the "water test" (see link above for instructions) to determine if your stone needs sealing or not.

Polished marble often is very slow to absorb, and thus, at very low risk for staining. Such stones typically don't need sealing since they are already naturally stain resistant.

Also, if water takes a long, long time to absorb (15-20+ minutes), then it's going to be a problem to get the sealer to absorb as well. When a stone is already dense with low-porosity a sealer does not need to be applied.

If testing shows absorption in less than 10 minutes on you floor and vanity, then it may be a good idea to seal it to guard against stains. This won't guard against etching of course.

The shower is different only because of all the water. For nearly all other stone the water itself is not a problem and usually sealing a shower is unnecessary.

However, with white marble you have possible iron deposits in the marble that can rust if exposed to water causing rust stains on your marble shower tile.

For this reason, white marble tile showers should be sealed to prevent water absorbing and possible rust stain.

For dense surfaces like polished marble where getting the sealer to absorb can be difficult... you need to use a sealer that absorbs better like Senguard Sealer rather than a standard sealer.

marble mosaic on shower floor
by: Anonymous

We were planning to use a marble lattice moasic on the shower floor.

It is made of: Athens Gray, Asian Statuary, Wooden Beige
Finish: Polished
Sold by the Sheet- each sheet measures 13"x13" (1.17 sq.ft.)
Thickness: 10 mm

Would you recommend sealing this product if placed on shower floor since there is some white marble mixed into it?

And other care info I should be made aware of?

==== Countertop Specialty comment:

I would check with the manufacturer first, but yes.... white marble is the one exception where a shower should be sealed in order to keep water from oxidizing possible iron deposits that are common in white marble.

Carrerra White Marble Shower
by: Anonymous

So I read your comments .... we have installed Carrera White Polished Shower Tiles (we had them installed) in our walk in shower, around the shower sill, around the marble vanity, and then larger tiles on the floor.

Do you recommend sealing ALL or just outside the shower area?? Thanks in advance.

==== Countertop Specialty comment:

White marbles like Carrara can develop rust like stains due to oxidation of iron deposits within the marble. Oxidation can occur with repeated cycles of water absorption and evaporation.

Now, water absorbing is not a problem for the marble. With most marble there is no need to seal simply to keep water from absorbing (i.e. in a shower).

However, you do want to seal white marble, Carrara marble in order to prevent rust / oxidation stains from water contact.

I suggest applying a sealer to all surfaces that will be regularly exposed to water. Certainly in the marble shower, but possibly the floor, vanity top, etc. No real need to seal any walls outside the shower though.

happy,happy,happy I read this!
by: julie

We just invested so much in the marble and Granite. So you know we want to keep it new forever!

This article kept us from putting anything in our shower (floors, seating, walls). We only had to do the large floor of marble. cha ching!

And the granite counter tops are a dark gold, brown & black, so, nothing to do there! cha-ching! thank you

===== Countertop Specialty comment:

Just FYI... your granite countertops may need sealing. Darker colors often do not need a granite sealer, however, the only accurate way to know if your specific countertop slab should be sealed or not is to perform the
water test for sealing granite.

Thank goodness for this artical
by: Anonymous

I didnt buy marble for my tub area for it to be another headach of having to baby another project around the house. After doing the lemon and oil test it seems i have a very hard polished marble that is not porus and does not have to be sealed like most other sights tell a person that they should. Thank you for this artical

by: Alvaro Castellanos

very good article good description

Click here to add your own comments

Return to Granite & Marble Sealer Questions.


Protected by Copyscape

buy granite cleaner, sealer and marble cleaning products

Let's connect!    Follow us:


home improvement contractors