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.


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


Can I install floor tiles on my shower walls?

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


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


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


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.


I have a 100 sq foot room,slab on raised grade. I have Rehau above floor radiant panels with 1/4 ” hardi backer fastened with 3/16 tap con screws every 8″. I did not install vapor barrier on top of concrete. It has a 1/4″ ply glued and fastened,from previous floor. Its nice and flat floor. It is ready to set tile. I am thinking this may need Schluter dietra ? Please advise.



Bevelled subway tile in a kitchen: should I lay it out in 1/2? or in 1/3?



Hi Sheri,

I prefer 1/2 with 3×6. You didn’t say what size they are.



Good morning I came across your page in moment of desperation! I am having my entire home tiled. The tile I purchased is rectified tile , it is tile that looks like wood. the tile installer told me my floors were uneven and he has started to install but the thin set under is raising my floor to be an inch higher that it was, is this normal ??? please advise! I can find nothing online about having to raise your floor. My installer told me he lays the floor like marble which is why he has had to raise it otherwise my tile will bow.



Hi Tiffany,

It sounds like he is doing a mud deck beneath your tile. No, it isn’t required. It’s only one method to create a flat substrate. Granted, it is the best method to do so, but the height is the issue with it. Ask him about slc instead.



We’ll be having a house built in Thailand in the next couple of years and the way they lay floor tile is a lot different than the way it is done in the US. The Thai tile layers will put down 3 to 4 inches of mortar on top of the concrete sub floor and keep everything nice and level. It seems like a lot of work and use of material to me or is this the best way to go about it? I would add a photo but I don’t see a way to.



Hi Frank,

That is actually one of the best ways to do it – old school mud bed. Works very well.



Hi, ok so I tiled my shower floor with a 12 by 12 of small square tiles with pre quarter inch grout lines recommend from tile store guy. I get to the back of my shower Where it meets the curb and it’s a 3/8 inch gap. I go ahead and thinset it down I figured it’s not that noticeable in back I’ll just fill in with grout. Now I’m having second thoughts will that make my grout too vulnerable for cracking? I really dont have the money to redo it.



Hi Cliff,

That isn’t going to cause your grout to crack at all, only movement will do that.



I have have a larger neo angle shower with a shower seat sloped to drain correctly. No pan install has started yet. The drain was installed with using a liner in mind. with further research the Kerdi system seems to be the better way to go. They make a conversion kit for the standard drain.
Have you used this kit without issue?
If I stay with the liner does it run all the way up over the seat as a continuous membrane if possible. If not is the liner only in the pan and the kerdi comes down the walls and seat to meet the slope of the pan. seems like a possible water trap between the liner and the Kerdi?
Does any of your e books show proper set construction?
with the pre slope if i go to the corners the mid-wall will be lower at the same slope is it common to cut the bottom row of tile to keep the space between the wall and floor tile consistent or just make a straight line between corners and accept a greater slope to the mid-wall?



Hi Jim,

The face of the seat would be treated just like a regular wall, the liner would only go up about a foot. Yes, I have used the conversion kit with no issues. The kerdi would come down over the bench to the bottom of the wall (or bench face). Gravity deals with the ‘water trap’. I do not have seat construction in the manuals, but I do have a write up on them: Creating a shower bench. The perimeter of both slopes remain level all the way around, your slope will vary depending on how close the wall is at that particular spot to the drain. It could be 3/8″/foot or more, as long as the slope from the drain to the furthest corner is 1/4″/foot.


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