Tile FAQ’s

The list below contains some of the most commonly asked questions I get about tile and installation methods. For each one I have included a (very) short answer.  I already have, or will have in the future, a post about every one of these. If that post already exists there will be a link at the end of the answer.

I will continue to add to this page as the questions come up. If you have a question just leave a comment at the bottom and I’ll include it on this page.

Just click on the question to view the answer.

Grout

What type of grout should I use for my tile?

It depends on the tile and the size of the grout lines. Read this: Using the correct type of grout

How large should my grout lines be?

It depends on the tile size and the look you want. Read this: How large should grout lines be?

Can I fill my cracking grout with more grout?

Maybe. Read this article for a more complete answer: Filling grout lines with more grout

Are there any “magic” products available to remove stains from your grout and tile?

No there are not. One of the closest things to magic that you can buy is oxygen bleach. It is not bleach! It's a slight misnomer. This is the main ingredient in products like oxyclean. It works very, very well to clean grout. More information: How to clean grout

Does grout help stabilize tile, hold them in place, or make them stick better?

No it does not. (Epoxy grout is different) Read this: Does grout stabilize tile?

Are tile, stone or grout waterproof?

No they are not. Read this: Is tile waterproof?

Can I install my tile without grout lines?

No, you should not. Read this: Tile with no grout

Miscellaneous

Can I install floor tiles on my shower walls?

Yes you can. Read this: Floor tiles on a wall

Sealers

Will sealing your tile and grout make it waterproof?

No! It absolutely will not.

Should I seal (or re-seal) my tile and grout?

If you would like it to be easier to clean then yes, you should.

Setting Materials

What should I use to set my tile?

It depends on where you are installing the tile. Read this: Proper setting materials for tile

Are mastic and pre-mixed “mortar” acceptable to install tile on a floor or in a shower?

No they are not. Read this: Proper setting materials for tile

Substrates

Does my floor have to be level before I install tile?

No it does not. Read this: Does my floor have to be level for tile?

Do I need a waterproof membrane for my shower walls?

Yes, a membrane of some sort is required. Read the article for the different types. Read this: Preparing a shower wall for tile

Can I simply stick tile to the drywall in my shower or the plywood on my floor?

You can but it won’t last – so no. Read this: Preparing a shower wall for tile or this: Installing backerboard for floor tile

Transitions

Should I use grout or caulk in the corners of my shower?

Technically? Caulk. Realistically? It depends. Read this: Caulk or grout in corners?

If you have any suggestions or questions please feel free to leave a comment.

Lisa

Hi Roger,
I am in the process of installing Hardie backerboard on my pine wood walls in my kitchen for a tile backsplash. I am getting conflicting answers from The Tile Store regarding the perimeter of the backerboard on the walls. There is going to be a very slight gap where the backerboard meets the counter top, but do I have to leave a gap where the backerboard meets the bottom of the cabinets, and where the backerboards meet each other?

Thank you in advance.

Lisa

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Robert

Hey Roger I have a question about wood stud blocking behind Durock. It’s my understanding that you have to place blocking whenever you have a free “floating” backer edge not supported by framing. This is confusing because you are supposed to do it mid wall where Durock seams are perpendicular to studs but no one seems to worry about it where the free Durock wall edges meet the floor or ceiling.

1- Should I be blocking free edges at the floor and ceiling?
2- What about around HVAC vents between studs where there is no stud support?
3- Durock seems to have some play when I push on it between studs 16″ OC. Does this harden up significantly when I apply thinset and tile?

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chris

I need to install a corner shelves/soap dish. What do you think of the kind you adhere to the tile after the tile has been installed vs. installed with thinset at the same time tile is installed?

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chris

Hi Roger,

I have a couple questions for you if you don’t mind:

1.) when you fill changes of plane (I’m using tile/Durock into wood studs) with silicone before mud and mesh, how far up do you fill with silicone. In other words how thick a layer of mud should be on top of the silicone to have enough strength.
2.) Do I use this method just in the tub walls/ceiling or also where the floor meets the walls and the other corners of the bathroom?
3.) How do you prevent that nasty look with silicone where it appears to lift up and get dirty at the edges over time?
4.) What the best way to remove old silicone. How difficult is it to do?

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Kay Nelson

I am getting ready to – for the first time – use the Schluter Kerdi on an existing shower. The walls were onyx but have been removed. The existing shower pan is onyx. The Kerdi will go over existing sheetrock. How should I seal between the existing pan and the sheetrock? Should I use the Kerdi-Band with Kerdi fix or just the Kerdi-Band? There is a small gap between the bottom of the sheetrock and the shower pan.

Appreciate any help you can give me.

Kay Nelson

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Jesse

Roger,

I am installing a tile countertop in my kitchen. The tiles have a rounded edge on the face and are slightly flared at the base. Butting the tile together leaves a decent size gap for grout, somewhere between 1/16-1/8. Do I need to use spacers so that the grout touches the thinset or am I fine butting the tiles together. Thanks.

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Jay

Roger,

I downloaded your book and follow your advice and used hydroban over cement board. When i went to pick up my tile from the tile store what was supposed to be a porcelain tile is in actuality a dry pressed ceramic tile with a water absorption rate of E>10%

When I questioned the owner of the store about the difference in material and absorption rate from what was on the display board and I was told the tile would be just fine in a shower as long as it was not a commercial shower or sauna.

Obviously I am leery about putting up a tile with such a high absorption rate in a shower and I would not have picked this tile if the display board was correct.

Should I be concerned?

Thanks
Jay

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Roger

Hi Jay,

Provided your shower is properly waterproofed you don’t need to be concerned at all. The limitations on a sauna or commercial steam room is because it would be infusing vapor into the tile, which would cause them to swell over time. A regular shower is not going to be an issue.

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Frank Fey

I finished installing the tile on the back wall of my shower and I was wondering if filling in the gap between the front and back wall with silicone before installing the front and back tiles would help improve the water tightness. Just thinking I would have two layers of protection before reaching the backer board.

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Roger

Hi Frank,

Completely unnecessary if your shower is properly waterproofed, but it won’t hurt anything.

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Alan Strassberg

What’s your opinion of “greenskin” as opposed to backerboard for substrate for a small bathroom? A bit pricier, but looks easier to do and saves the extra added height.

https://www.youtube.com/watch?v=fvOrYQ9gBiY

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Roger

Hi Alan,

It works extremely well – I’m a fan of greenskin.

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AT

hi, I have white porcelain floor tiles which I feel is a little too washed out. I want to enhance the brown and gray in the tiles, as well as the grout. I like my floor better when it is wet. I am wondering if enhancing sealer will help little? I haven’t sealed my grouts yet.

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Roger

Hi AT,

It may, it just depends on the porosity of the surface glaze. It won’t hurt, so it’s worth a try. Worst case scenario is that it won’t enhance the coloring, but it won’t hurt the porcelain at all.

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Cindy

I have a someone who has worked on my shower and has used beautiful mosaic tiles and stones for the low side walls and floor. He used Tec Power Grout 550 and unfortunately, did not wipe the stones and expose ALL of them prior to the grout setting. Please let me know if there is a way to remove some of the grout to expose these stones. I notice that he tried to sand them in certain areas and I asked him to stop until I did some more research. As he was sanding them, he was ruining the stones and it appeared that he was leaving a “burn” like finish. Help!?

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Roger

Hi Cindy,

I don’t know of anything that doesn’t have the potential of ruining a stone. Sulfamic acid will remove the grout, but I don’t know how it will affect your stone.

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Angela

Hi, we are getting ready to put in a handicap accessible bathroom for our little girl and would like the whole thing to be a wet room so have read through a lot of your things on how to go about doing this. I do have a question though. Does anyone make a slip resistant tile or similar floor type for a shower/bathroom? This is extremely important for us to have for her and I haven’t had much luck finding options. Would it be easier to go with concrete floor? From what I read it sounds like the concrete wouldn’t be waterproof though? If you have any recommendations on the best way to make this bathroom we would really appreciate it. We need to go as cheap as possible and none of our volunteers are well versed. Thanks in advance for any advice you can give…

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AT

i just read that some Impregnator Penetrating Sealer
will help some tiles become less slippery.

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Roger

That’s true.

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Roger

Hi Angela,

No, concrete is not waterproof. The ‘slipperiness’ of the tile is noted by the coefficient of friction number indicated by the manufacturer.

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Terry

We needed to add a bedroom and bath to our house for my mother-in-law. When it came time to tile the bath we hired a “professional” who was recommended by the builder. Maybe I shouldn’t get into how I really feel but tell you what the end problems are. I’m willing to accept most of what was done but can’t accept how it looks at the bottom where the walls meet the floor. But first I must tell you that the floor was prepared so that we could “drive” a wheel chair in so it has no lip, just a hump. Inside the shower there is at most a half inch space between the wall and the floor but that varies down to nothing. Before the kid, who the professional assigned to the job, finished with the wall outside the shower we asked them to leave. So what we have left is what to do with that space. He just left it with whatever he used to attach the shower tiles to the walls and it’s impossible to get out. We had to caulk over it for her to use but now need to fix it properly but that’s the question. How? I can send pics and get you product details if you can help us. We have now finished the walls outside the shower except for grouting and I think we did a pretty good job. We also tiled our kitchen floor and back splash.

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Roger

Hi Terry,

You can get the thinset out of that space using a roto-zip or a dremel with a tile bit on it. You can cut tile down to fill those spaces so you have a consistent 1/8″ space between the wall and floor tile, then silicone it.

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Heather Sato

Hi Roger,
Great info here, thanks so much. My question is regarding deflection (up/down bounce). Using the John Bridge calculator looks like our house was built with a deflection of L/321 for the vinyl floor that is there now. From what I can find I need L/360 in order to install tile. Our joists are 2×6, and span of support is 8 feet. We have a wood subfloor that runs on diagonals, typical for a 1950’s house. The tiles we are looking at are the ones that look like hardwood and are 6″ x 2.5′ long.

Here’s the question: If we put in 5/8″ plywood and do as you recommend, thinset the 1/2″ Hardiebacker + mesh tape/mud/1-5/8″ Backer-On screws, do you think our tiles will crack?

I’m worried the length will crack because our floor wasn’t built to hold the weight…

Many thanks!
Heather

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Roger

Hi Heather,

I would use a 3/4″ layer of plywood, then thinset and backer. I think you’ll be just fine with that.

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Natalie

Hi Roger,

I read your tip book very good, my cousin in USA told me about your website! its been great!

we are about to undertake renovating our small bathroom and our shower area is quite small. We are trying to do it on a budget and was going to use the existing shower screen/glass.

currently the tiled hob is measuring 91cm x 91 cm x 9.5cm thick.
I have about 5 cm between the current hob and the cornice (may not be the right word) /door frame and I was wondering if I move the hob right out to the door frame do you think it will be possible to brick up/tile the other wall and attach the glass to the extra brick section rather than the wall?

My plan was to use 5 cm thick/wide bricks on the new hob so that would essentially make my new hob 91cm x 96cm x 5cm (plus the thickness of the adhesive & tile) and on the side that is 96 cm I would put a wall of brick up to the top of the shower glass and use a feature tile over that area.

I hope what I am saying makes sense and do you think that will be viable?

Could I also gain more room by cutting those hebel bricks in half and making a 2.5cm hob? or is that too thin for a hob?

thanks!
Natalie

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Roger

Hi Natalie,

2.5cm is too thin for a hob, in my opinion. It MAY work, but I wouldn’t trust it. No reason you wouldn’t be able to attach the glass to the extra brick with proper anshors.

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Laurie

I have a shower with 2×2 tile floor (sanded grout) and acrylic faux marble walls. The floor is not square in any corner so the installer apparently worked back from a tight fit against the rear wall. That rear wall transition was caulked; the other 3 were grouted in spaces ranging from 1/8″ to 1/2″. The grout has separated from the acrylic wall in several places; I need a fix that can last a while until we are able to renovate the bathroom. My understanding is that caulk won’t adhere properly to grout, but I think the spaces are too large to remove the grout around the perimeter and use just caulk. Thanks in advance for any suggestions!

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Roger

Hi Laurie,

In any change of plane (wall meets floor) you need to have a flexible sealant. Grout will simply crack (but you already knew that). You can just dig out about 1/8″ of the grout from whichever side is coming loose and fill that with silicone or caulk. That will normally work as the grout is not contacting both planes.

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Laurie

Ok, thanks for the advice!

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