View Single Post
Unread 10-21-2020, 04:38 PM   #2
Veteran DIYer- Schluterville Graduate

STAR Senior Contributor

Join Date: Jul 2004
Location: Nashua, NH
Posts: 14,203
First off, CDX plywood is a no-go for tile installations! Industry calls for at least C-faces as the worst ones. The D-face, aka voids, is a red flag for any tile installation.

Industry standards call for two layers of ply, properly installed for any natural stone tile.

The size of the tile has no effect on how strong the structure needs to be or how it is oriented relative to the joists. Nor does the thickness of cbu which is a tile compatibility layer, not an indication of strength.
Jim DeBruycker
Not a pro, multiple Schluter Workshops (Schluterville and 2013 and 2014 at Schluter Headquarters), Mapei Training 2014, Laticrete Workshop 2014, Custom Building Products Workshop 2015, and Longtime Forum Participant.
jadnashua is offline   Reply With Quote