Does my Floor have to be Level to Install Tile?

by Roger

Before installing tile on your floor you must make sure your floor is properly prepared.  A properly prepared floor does not have to be level. It must, however, be flat.

The only time the levelness (is that a word?) must be taken into consideration is when drainage is an issue, such as on a porch or in a shower. In those cases you must make sure your floor is not level – it has to be angled toward a drainage area.

If your floor will not be subjected to water regularly, such as a kitchen or bathroom floor, it does not necessarily have to be level. That does not mean you can have a 45 degree angle from your door to the cabinet (although I suppose you could if you wanted), it just means if your floor is not absolutely level it will not negatively affect your tile installation.

One of the things you must make sure of, among other things, is that your floor is flat. If it is not it will be difficult to set your tiles without what we call “lippage”. That’s a ridiculous word, isn’t it? Lippage simply describes the difference in the height of two adjacent tiles. If you have a tile that sticks up higher than the tile next to it you have lippage. You don’t want that. Starting with a flat floor helps prevent it.

When prepping your floor for tile trade your level for a straight edge. Don’t be concerned with how level your floor is, be concerned with how flat it is.

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Ryan

Roger,

SOS… I have a bathroom in remodeling right now it’s 8′ 6″ x 12′. I replaced the subfloor with 3/4″ advantech T&G and then added a second layer of 3/8″ plywood over it. I am using a ditra uncoupling membrane and 36″ x 6″ porcelain tiles. Here’s my problem… I checked my floor (or thought I did) for level before laying the ditra. Tonight i was cleaning up and noticed my level laying on the floor and against one wall the floor is 1/4″ out over about 16″. The rest of the floor is flat and level but up against this wall (8 one of the 8′ 6″ walls) the floor slopes! Is there anyway to correct this now that the Ditra is already set?

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Ryan

Maybe this is a dumb question… The mortar I’m going to be using to install the tiles is Mapei Uncoupling Membrane Mortar. Since I’m using LFT tiles this is a medium bed mortar. My understanding is that medium bed mortars are made to be applied thicker than a thinset. Could I use the medium bed mortar over the ditra and build it up 1/4″, let if cure then come back over it with my tile?

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Patrick

Roger:

I just finished a few days of intense vinyl tile and old linoleum floor removal. Should I survive to fight another day, I intend to get to the ceramic tile my wife picked before she changes her mind.

My question is this…… There is a concrete subfloor to work on, but there are some areas where the removal process has left it less than perfectly smooth and even. The discrepancies are minimal. Basically the thickness of a sheet of paper or two.

Do I need to make the floor perfectly smooth before I proceed, or will the thinset be thick enough to account for those differences? I’d hate to have to hit the entire floor with a sander, but worse things have happened.

Thanks

Patrick

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Mandy

I’m not a professional but I just had my floor done with the same situation you have, and the tile person who laid my tile down went on top of it all, unfortunately there is severe lipage all over my floor. Looks like a third grader did it. And supposedly this guy has 20+ years experience. I am extremely dissatisfied. So if I was you I would get it as flat as possible

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Dave

The subfloor where I am building my shower is sloped almost 1″ across five feet. I am using a Kerdi shower floor base with its built-in slope, but I really think the subfloor should be level underneath. Should I use SLC (and then thinset after it’s cured), or not worry about the slope? If SLC do I need to use bonding primer on the wood?

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Kelly

Hi,
I have a bathroom we are trying to tile, the room is narrow and long, and the big hiccup is the floor at the outside wall is Higher than the floor that meets the hallway. (So the tile would be 1/2″ taller by door into hallway floor) Think a very slow incline ramp as you walk into the room.
Any input on how to work around this issue?

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Jason

Hi everyone,

I have a guy doing a complete reno on my 10’x9′ kitchen. He just put in 12″x24″ tile flooring. The grout has not been laid yet though. There is noticeable “lippage” in some spots and the floor was not made flat so some tiles are off by maybe an 1/8 or 1/4 in (a few are going to be under the fridge). Also, he didn’t use spacers so the grout lines arent going to be perfect. It should have an 1/8 in grout line and some tiles are almost touching. Im a bit obsessive about straight lines with things like this and these are definitely not straight. Should I bring it up at this point or just live with the crappy job? He’s friends with my girlfriend’s parents.

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sdu754

You should definitely say something. Just because the guy is friends with someone you know doesn’t excuse him doing a half ass job. I would be worried about the job he did preparing the subfloor if he can’t get the grout lines right. Not using spacers is just plain lazy. I’d make him pull up the tile and do it right.

A poor tiling job can really hurt the ability to sale the house if you decide to down the line. Nobody is going to want uneven grout lines, or uneven tile for that matter.

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judy

2 questions,
1 .I just had a floor installed with 42inch tile . The installer ended up doing some kind of a mud job because he said my house was old and very uneven . i now have big difference in the rooms that were not tiled, They put moldings likes stuff there to make it less noticeable but it is still awkward. I have always been told make it flat not level. Did he do a bad job or did he do it the right way?
2 ,did a bathroom ,installer put mud on top of the cement board because he said with the brick design he would have have 1/4 inch pieces on each end so he built it out so that would not happen. the problem with that it that the shower facets and handles need extensions and will not sit flush and instead of 1/4 tile I have floor 1/4 ,1/2 in some spots to ceiling on 2 sides of the showers bull nose .Any suggesting?
Thanks
Judy

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sdu754

The tiled areas will be naturally higher than the non tiled ones. If he tiled over a wood subfloor, which he most likely did, he has to use 1/4 inch cement board to make the floor sturdy enough. The floor tiles add another 1/4 inch, plus you need to use thinset mortar between the tile and cement board, and it’s highly recommend between the subfloor and cement board as well. Unless he pulled out over 1/2 inch of flooring, which is highly unlikely, you are going to have floors of varying hight. You also need a reasonably flat and level floor to tile properly
The only reason to tile an uneven floor is if you have a floor drain. If he put down transition strips you should be ok and able to adjust to the varying hights with time

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George

George

Hi Roger,

Thanks for setting me straight with my grout question. This is my second question about the porch floor I am installing with the mosaic. I attached the photo to remind you what it looks like. As I said in my earlier grout question, I am tiling a floor where the center of the room will have a decorative rectangular mosaic piece. That piece will be framed with border tiles. The rest of the floor will be ceramic tile. My problem is that the mosaic will be thinner than field tiles, perhaps by 1/8″ and it is possible that, depending on tile choice, the border tiles may be slightly thinner than the field tiles but thicker than the mosaic. I am wondering what is the best way to handle this.
I considered just using a heavier layer of thinset but this is a real mosaic and I am concerned about the thinset coming up through the small mosaic tiles and screwing up my grouting. Also, I don’t want to have to mess around with pulling up the mosaic because I used too much or not enough thinset to get the right height. That would be a mess! I’m thinking that if the border tiles are a little thinner than the field tiles then that’s where I would just use heavier thinset. But what do you recommend for the mosaic? I read the post about using Ditka as a backer but I think that would raise the mosaic too much.

One thing I thought of is, before putting the cementboard down, I would put down a spacer for the mosaic that is just thick enough to bring it up to the proper finish level. When I installed the cement board, the surface would be uneven but when the tiles were installed they would all be at the same level. A possible problem I see is that the cement board joints would align with the joints between the different tile types. Is this an issue?
Thanks

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Erick Richards

Where can I get medium (not thin) unmodified mortar? I may need to put down about 6/8s of mortar on my floor to make the bathroom tile level over ditra. Any suggestions would be appreciated.

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Paul Radvansky

Hello

I am building a new walk in shower and created a rubber membrane underneath my concrete base. Then i noticed that the pitch was not good in some spots and I added about 1/8 inch of floor leveler on top concrete. Is this okay or do I have to remove it some way?

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Roger

Hi Paul,

It’s fine.

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