Tile FAQ’s
The list below contains the most commonly asked questions 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 the question will be a link to the article.
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.
- Can I install my tile with no grout lines? No you should not.
- Are tile, stone, and grout waterproof? No they are not.
- Does grout help stabilize tile, hold them in place, or make them stick better? No it does not (Epoxy grout is different.)
- Are mastic and pre-mixed “mortar” acceptable to install tile on a floor or in a shower? No they are not
- Are there any “magic” products available to remove stains from your grout and tile? No there are not.
- Should I seal (or re-seal) my tile and grout? Yes you should.
- Does tile require a lot of maintenance? Not a whole lot but it is by no means maintenance free.
- Will sealing your tile and grout make it waterproof? No it will not
- 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.
- Can I fill my cracking grout with more grout? Maybe. Read the article for a more complete answer.
- Should I use grout or caulk in the corners of my shower? Technically? Caulk. Realistically? It depends.
- How large should my grout lines be? It depends on the tile size and the look you want.
- 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.
- What should I use to set my tile? It depends on where you are installing the tile.
- What type of grout should I use for my tile? It depends on the tile and the size of the grout lines.
- Can I install floor tiles on my shower walls? Yes you can.
- Does my floor have to be level before I install tile? No it does not.
If you have any suggestions or questions please feel free to leave a comment.
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Hi Roger, thanks for the education thus far.
I’m starting a shower remod and boy do I have some questions. I have demo’ed the walls back to the studs (16″ OC) and will be building a shower where a tub once sat. I still need to move the back wall out to enlarge the shower footprint. My vision is to install 12″ x 12″ marble tiles with small glass or tile mosiac accents over Kerdi membrane and a drywall substrate. Smaller marble pieces on the ceiling and over a mortar shower floor. And this brings me to my first question, I know that the manufacturer recommends a drywall substrate under Kerdi, but really? I’ve been married for 20 years so I obviously know how to follow directions, and I am confident that I can create a watertight barrier. But, I could “what if” this to death, when the frameless glass surround is installed the mounting screws will breach the Kerdi, if water gets through to the drywall… game over!
Why wouldn’t a c.b.u. substrate be a better medium?
The new back wall to be framed will be 2X6′s, again 16″OC. I am going to build a niche in this wall and for aesthetic reasons would like it to be wider than the approximate 14″ between studs. Framing is no problem, but with a plywood backing (5/8″ or 3/4) can I run this niche out to 20-22 inches? My concern here is flex and instability due to the unsupported width.
You steted in other print that you liked Marble, as do I. Is marble suitable for the floor tile if I keep the pieces small or can it be too slippery? How often does it need to be sealed?
And finally… if a dog bursts into flames, will a unicorn fart put it out? I’m just sayin’
Thanks a bunch,
Dumas
Hey Dumas,
cbu is a better substrate – and you can use it if you want (and it will help you sleep at night), no problem at all. Any penetrations through the kerdi needs to have silicone filled into the hole first, then the screw. That’s true with drywall or backerboard.
The maximum size you want on the shower floor are 2×2′s. Anything larger will be slippery.
Not sure about the dog flames and unicorn farts – I’ll test it in the garage this weekend if I can get approval from the wife.
Hey Rodger, I feel like a broken record over here, but great site. I would have liked to use a more eloquent superlative, but great sums it up nicely.
About 5 years ago I talked the wife into buying a 1970′s fixer (best neighborhood, worst looking house mentality), rather than a “new construction” home based on two facts: 1. The “new” construction, since 2000 or so, is pretty much crap, in my humble opinion. Using 2×3′s rather than 2×4, stud spacing at 24″ rather than 16″, running an entire kitchen on a 15 amp circuit, etc. Basically anything they could scrap to save money and hide from the inspectors they did. And 2. They just don’t build them like they did in the 1970′s! Great bones of a house is an understatement, more like brick silo.
Nothing infuriates me more than lazy labor. If you are going to do it, do it right the first time. Sorry, I’ll put the soap box away.
I am in the process of giving the wife her dream hall bathroom (this after giving her the dream kitchen, dream master bedroom and bathroom, dream nursery, dream office, you get the point), and in reading your masterpiece on the waterproofing, I didn’t see anywhere that you specifically addressed how exactly to continue the waterproofing around the shower/tub valve. In the traditional method, of using 6 mil against the studs, how do you incorporate the valve? In the flawed section, picture 19, could you please elaborate on the correct way?
Hey Garris,
I absolutely agree about new construction! Well said.
You want to silicone the vapor to the back of the backerboard to create a ‘dam’ around the valve. When water runs down the barrier it will hit that bead of silicone and run around it rather than into the wall cavity. As you install the tile you want a bead of silicone around the valve sandwiched between the tile and backer – same reason. Those coupled with the escutcheon seal prevent any water from getting in there.
Thanks Roger,
I guess the floor In 2×2 should also be diagonal? It adds a Lot to the price. Linda
Doesn’t need to be, they’re small enough that it won’t look funny if they are installed straight.
I am having my kitchen floor tiled, it has linoleum now. Does the linoleum have to come up or do you wonderboard over it.? Thanks
Hey Dave,
As long as it is not ‘cushioned’ linoleum you can place thinset over it then screw down wonderboard.
Hi Roger,
Right now our entire shower including floor, walls, niches and corner seat are covered with Hardibacker. We need to tape the seams.
In some outside seams, the Hardbacker did not meet perfectly, and now we have – how to explain - tiny inside 90 degree corners. Just imagine the shower niche… the sill piece being a little short and not covering the vertical piece. So there is a gap like this: L (sideview.) The vertical part of the L and the Horizonal part just meet at the corner, but do not cover each other to create a perfect outside 90 degrees. Using the corrent cement board tape and thinset, how do I fill those areas and make them square? I want it really smooth and nice because I will be applying Hydro Ban to the entire shower and feel the smoother the corners are the better. I would be happy to send you photos if you are willing to send me your email address. Better yet, you could just fly to Austin and give me a hand. The weather is great now. haha. Appreciate any guidance.
Thank you!
Larry
Hey Larry,
You can build up the area in the low part of the ‘L’ to be flush with the upper. Let it cure, then tape and mud everything. You can use sandpaper to sand everything down smooth wherever it didn’t end up that way. I would head down to Austin but, you know, it’s in Texas.
Correctioin—My tile comes in 12 x 12, which I’m now considering for the ceiling. Given the horizontal brick pattern of of the walls, would you recommend diagonal for the ceiling? And stay with 2 x2 for the floor?
Correction – the 12×12 would look good too.
Diagonal always looks better with subway patterns.
I am tiling my bathroom floor with an off white (with some subtle shading changes) Italian porcelain 12 x 24 in a brick pattern. In the small shower, I plan to use the same size and pattern running horizontally. My problem is what to use for the floor and ceiling. The tile comes in 2 x 2 mosaic, but then jumps up to 18 x 18. Do you advise using the small tile for the floor? Cutting the larger pieces to a smaller size for the ceiling? THanks for your help!
Hey Linda,
You NEED to use the smaller mosaics for the floor. They will conform to the shape of the shower floor, larger tiles will not. You can use any size you want on the ceiling – the 18×18 would look good. No reason to cut them down unless you want. When installing a subway pattern around a shower you will not be able to keep all the grout lines matched up – they will be offset somewhere – it’s just the nature of the pattern.
We are installing an alcove bath tub with a flange ( lip) that is about 3/16″. I see where you advise to install cement board 1/8″ above the flange. Do you then suggest that I mud and tape the gap and the flange to prep for the tile, leaving a gap for caulk? Please help.
Hi Sherry,
Nope, you don’t need to do anything with that gap at all. The moisture barrier needs to run down over the front of the lip and the back of it is siliconed to the flange, backer 1/16″ – 1/8″ above it, then the tile just hangs over the front of it down almost to the tub itself. Anything you place between the tile and tub will just crack and cause problems.
Ex contractor put in 1/4″ sheet and 1/2″ sheet of plywood over floor joist under new fiberglass tub. Is this strong enough for support? Floor Joists are 16″ apart. Tub is perpendicular to floor joists.
Hi Tina,
While not ideal it should be fine. It should have been at least two 1/2″ sheets. Who the hell uses 1/4″ plywood for anything? (rhetorical question – nobody does…)
Hi Roger
In our bathroom re-model we are stuck @ out flange. A full piece of tile would go there with the flange to the left of tile. There would be about an 1 1/2 part of the tile, then the circle for the flange.
My question???? what is the best way to cut the circle to fit over the flange
Thanks bunches and want you to know I just love your site. U B da boss….lol
Hi Elizabeth,
The easiest way is to shift your layout one way or the other by 1/2 tile.
But that isn’t gonna happen – you and I both know it. A grinder with a tile blade on it will cut that circle out for you.
Hello Roger! Great site! So happy i stumbled upon it. I read through alot of it but wanted to ask you something about my specific project. I just completed my 1/2 bath remodel including a 12×12 tiled floor (1st tile job for me which came out pretty good) but now have to do 1 of my full baths. Ive never tiled a shower stall before but am going to give it a shot. Its a 32×48 shower and i plan to use a swanstone shower pan (is this a good pan do u have any experience with them?) From what it looks like they tell you to place it in a bed of mortar. I also plan on using durock for the walls, then tile them with 12x12s.
1 is an exterior wall in the shower. I was going to remove the current insulation and use spray foam. Will this be a benefit? I think it should provide a better r value maybe and be more resistant to mold than fiberglass correct? I also wanted to use insulation or some sort of sound deadener in the interior wall cavity as there is a guest bedroom on the other side and the shower can be loud when running. Is this ok? Should i use 4 mill plastic on all walls then staple and glue it to the studs? Or just staple? I can just screw the durock to the walls - is there a benefit in using liquid nails with it as well?
Also, since i will be securing the shower pan directly to the wall studs do i bring the durock all the way down and over lap the lip or just bring it to the top and over lap with tile? And then caulk underneath the tile? Is there a benefit to using a ledger board or can i just start the tiles from the bottom up?
Sorry for the novel but would really like to get an experts opinion on all this. THANKS!
Hey Alex,
The r-value of the spray insulation may or may not be better than the fiberglass – it will state the r-value on both products. If (WHEN!) your shower is build correctly you don’t need to worry about mold at all – ever. But for the record mold eats mostly the kraft paper covering in the fiberglass insulation and the wood studs it’s stuffed between, if mold gets back there it doesn’t matter what type of insulation is there – it has plenty of food. Just staple the plastic to the studs – no need for the glue also.
Swanstone is a good product. The vapor barrier must run down over the lip and the back of it should be siliconed to the lip of the base. The backer can go to the top, or over the front of, the lip. Makes no difference. Tile goes down to the top of the base. I just normally start from the bottom up, I rarely use ledger boards.
Thanks Roger-so the vapor barrier does not go behind the shower pan to the floor then? I actually glue it to the front lip of the pan? Just want to be sure. Also, what type of trowel do u use for 12x12s? I have a 1/4 x 3/8 trowel i used for the floor in my other bathroom. Will this work?
Another question- since i am only tearing out the shower and butting up to the exisiting sheetrock i should use 1/2″ durock right? And what should i use at the gap from the durock to the sheetrock? Same thing im using on the durock seems? Alkaline resistant tape and mortar/thinset?
thx again for any help!
No, the barrier runs to the tub and is siliconed to the lip. When water gets behind your tile and runs down the barrier it needs to run into the tub. I use a 3/8 x 3/8 trowel, if your wall is very flat yours will work fine. Just be sure you have good coverage.
Yes, 1/2″ durock. The seam gets fiberglass mesh tape and thinset just like the other seams.
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