I am looking for ideas on how-to tile over 2" inches of XPS layed over a concrete basement floor. Ditra is very expensive and we currently have a few materials in stock that we would like to use.
We have 1/4 & 3/8 cement board and also 7/16 OSB and 3/4 plywood.
The foam will have routed pex tubing running in between. Then we planned on putting OSB screwed into concrete and then cement board with thinset and then tile on top. OR 3/4 plywood screwed into concrete and tile on top of that.
I was wondering what everyone's take on the install was. I haven't been able to figure out what the deflection of XPS would be. Its rated for 25psi compression.
Please direct us to the specification from a tile association or the manufacturer of XPS that says this type of installation is recommended. Need to read all the data including the fine print regarding its use below grade where there's moisture present.
TILE GUY - retired- TROY, MI - Method & Product suitability consulting.