Anyone know about ceramic tile?

Many tile floors have been put directly on plywood w/o problem. Generally, however, for best results it's recommended to use Durock (or your choice of cement board). Install the cement board to the plywood with thinset and screws, tape the seams, then lay the tiles in thinset. Seems like the cost of "doing it right" in a relatively small area like a kitchen would only be a bit more than skimping ....

Use the underlayment.

Doing it right with the underlayment is a good idea, you might also want to look at what the deflection level is in your floor. Tile is very rigid material, and if you try to put it on a "springy" floor that flexes a lot when someone walks across the room, or you move the fridge, etc, you are asking for problems as the floor flexes and the tlles don't. Even in standard construction this can be a problem on a floor that wasn't originally built with tile in mind. Since manufactured housing is often built lighter I'd suspect it would be worse...

The John Bridge / Tile your world website has a calculator to figure out what your floor's deflection rating is, and advice on how to fix it if there's a problem, along w/ lots of other advice on tiling things... No reflection on the good folks here, but that site does for tile what we do for wood stoves

Gooserider

why not use the new tile laminates that are out. They look and wear great and install in no time. just click and move on.

I would never lay directly over plywood. I just think you are asking for trouble. I have now ripped up two tile floors (in homes I have bought) due to cracking and both were laid over plywood.
My last install I used Ditra. That stuff works amazing.
Just because you can do something doesn't mean that you should.

Installing directly over plywood is not a good thing. Yes, it can be done, but, one thing not mentioned is: Wood expands and contracts with moisture level changes. Also the plywood is probably not thick enough. If you have 2x10 floor joists at 16 inch on center, your plywood need to be a minimum of 1 and 1/8 inch thick. Then you could just install the 1/4 inch durock over that to get you an ideal surface for the tile to bond to (no expansion and contraction like the plywood).

Contrary to popular belief, cement board (durock) really does not provide much increase in strength to the subfloor. 1/2 inch durock bonded to your plywood subfloor of at least 3/4 inch thick (with 2x10 at 16" OC) will probably work, but technically not up to spec and problems can occur. What it does do is provide an excellent surface to bond the tile to. When installing durock, you need to leave a gap of 1/8 inch between panels, installl them in a brick pattern (stagger the joints) and fill the gaps between panels with thinset and then durock tape. The goal here is to make on big panel out of lots of little ones. You also need to leave a gap (I like about 1/4 inch) where the durock meets the walls and other verticl obstacles (again for expansion and contraction and normal movements when two planes meet). You do not fill these gaps, but caulk instead.

The link to the tile site is good advice as well as the info in the previous posts. Do your homework on that site and find out what thickness your subfloor is, it's supports (joists) and it's span length. Then go from there. Good luck. KD

d.n.f. said:

I would never lay directly over plywood. I just think you are asking for trouble. I have now ripped up two tile floors (in homes I have bought) due to cracking and both were laid over plywood.
My last install I used Ditra. That stuff works amazing.
Just because you can do something doesn't mean that you should.

Click to expand...

I had a tile floor installed over some old plywood in a part of an old house where everything inevitably shifts around some over time (stone foundation and big old timbers plus changes in season, weather, humidity...), even though it's basically structurally sound.

Some would say that's a recipe for failure

had the installer put the Ditra in- it's all flawless 3 years later. if you look up the history of tile floors, the ancients laid them on a floating substrate over a bed of loose sand, so as to decouple them from movements in the surfaces beneath. the ditra or other similar membranes basically achieve the same thing- without needing an army of laborers- of decoupling small to medium shifts in the subfloor from the tile. durock or whatever other rigid material will add reinforcing but will not achieve the same decoupling of forces

General rule of thumb: Have at least 1 1/4" of substrate on top of the stringers before ceramic goes down.

Czarcar, Frxdy, and kd460 are right on target. I've done a lot of tile and have used Durock, Hardy backer, and the Schluter Dritra product. The subfloor can't move vertically or the tile will crack. The Schluter Ditra mat is great for circumstances involving possible horizontal expansion but it won't handle vertical movement well. The concrete backers only provide for adhesion and really don't add much flexural strenght to the floor.

Good luck with it.

DON'T use ceramic, use porcelain. Porcelain can take any cold extremes and the 'finish' is all the through the tile, so if it gets chipped it is hardly noticeable, unlike ceramic. If you have the space and money, use the cement board.

sinnian said:

DON'T use ceramic, use porcelain. Porcelain can take any cold extremes and the 'finish' is all the through the tile, so if it gets chipped it is hardly noticeable, unlike ceramic. If you have the space and money, use the cement board.

Click to expand...

Yes, porceleans are nice, but, even more critical to use proper setting material (polymer modified thinset). The porcelean tile is so dense that you need the increased bond strength of the polymer modified stuff. Read labels! The bags of thinset provide nice little "how to" on each bag. It must say "suitable for porcelean tile, (non vitreous).

As I posted earlier a "minumum" thickness of subfloor (which varies depending upon span of joists", a good rule of thumb for a floor is two layers of 3/4 inch exterior grade plywood with 1/4 or 1/2 inch backer board on top of that. Of course, each layer of plywood (and durock) alternate so the joints on each individual layer don't "radio" through. Or in other woods, the first layer of a joint or seam is covered by the middle (or close to it) of the next layer of plywood. Same thing with the third layer (which is the durock). KD

Don't forget when putting down the durarock set it in thinset, and nail properly if the durarock is able to pop up and down it is just like putting it on plywood