I am installing 18 x 18 inch porcelain tile. The tile will adjoin/connect to 3/4 inch hardwood. I have read that I need to use 1/2 inch trowel for the thinset for 18 inch porcelain tile. If I use a 1/4 inch plywood underlayment, 1/2 inch thinset and the tile itself is around 1/4 to 5/16 inch deep, won’t the total installed height be higher than the hardwood? We have layed the tile and underlayment next to the hardwood and there doesn't seem to be a big enough difference to accomodate the 1/2 inch thinset. I know the thinset will spread out under the tile, but won't it still be too high? What will the finished height be? Should I use a different underlayment, like one of the plastic/vinyl matt products? If so, which one should I use and what height will it be?
Any other advise would be appreciated
I assume this is not a cement slab home.
And are you down to a 3/4 inch subfloor where you're putting the tile, or is there other material?
Does the subfloor have any 'give' when walked on (a proper tile job requires a floor structure that is able to handle the weight with minimum deflection, or you'll end up with broken or cracked grout lines).
You don't say where you are located, but ways of building things vary from area to area. When it comes to tile, I recommend to avoid the big box stores, go to a specialty tile store and they can answer questions on proper installation in your area. But I can't help but think the "1/4 inch plywood" is not the thing to use. Maybe 1/4 inch tile board screwed down in thinset, then the tile. A little experimentation to see how much the thinset will 'smush' when the tile is put on would be a good idea. Leave a gap between the hardwood and the tile for expansion and use a caulk that matches your grout, which is also available at the specialty tile store.This message has been edited. Last edited by: Re-mdlr,
I will go even further and say that no way should you use 1/4" plywood as an underlayment under the tile. Just the moisture in the thinset will cause the 1/4" ply to buckle.
You can go with a 1/4" cement board backer but with the thinset underneath it you are looking at a total thickness of about 3/8". The 1/2" trowelled in thinset will become 1/4" to 3/8". Add this to the thickness of your tile and you'll have your total height.
A Detra or similar brand of fabric backer will be very close to 1/4" in thickness, so you can save 1/8" there over a solid backerboard.
If it turns out that the tile top edge is going to be higher than the hardwood, there are many metal tile edge pieces that are tapered to various heights. These are installed on the tile side and are bedded underneath the tile with a finished sloped edge angling towards the wood.
I'm going to disagree slightly. But since I answered this question elsewhere, I think I'll just copy/paste for now.
Steve, still waiting for your reply.
Good thing you stopped by and asked cuz you're heading for a failure.
* Never use 1/4" plywood in a tile installation sandwich.
* Tile should go over concrete backer or a membrane such as Ditra.
* Thin set spread with a 1/2x1/2" trowel will raise the floor about 1/8" or a hair more, but less than 3/16".
* The most important thing is to be sure the subfloor system is stiff enough for tiles. We do not strive for a smooth transition as the #1 objective.
Let us know how the framing is built; type & size of the joists, species and grade if at all possible, (there should be markings on each), the on center spacing of the joists, the unsupported span of the joists. The type and thickness of the subfloor.
How old, basement or crawl space, overall condition, type and size of room, where are you located, who's doing the work and experience?
Tile 4 You llc - Troy, MI
Kerdi shower specialist - Ditra installs - Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong!
as Jaybee said, that's not going to be a half inch of thinset once it is smushed down into the tile's backing. back-buttering the tile is a good way of insuring you won't get loose ones, and keep the thinset fresh. stuff that is starting to crust should be dumped.
assuming you have a solid subfloor (1-1/4 minimum of solid plywood with 1/4 cement board, or a slab base) the Ditra solution is a good one. there is at least one copycat material in green instead of orange, but it's not been out that long and thus doesn't have a track record. let the tract builders prove it out
without a solid subfloor, you will have a mosaic floor in no time with big tile.
use a honking long level (or a really, really straight hardwood 2x4 with a level taped to it) to be sure the floor is level. if not, do so with self-levelling thinset before you Ditra, it can go under the cement board.This message has been edited. Last edited by: swschrad,
sig: if this is a new economy, how come they still want my old-fashioned money?
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