Good morning,

I am building a new bathroom with a custom shower. I am in the process of finishing up my plumbing and installing cement backer boards for the shower walls and on the bathroom floor. I plan to build the shower pan with mortor bed and PVC liner.

I will be using ceramic tiles that measure 16" x 16" x 3/8" for the shower walls and the bathroom floor. I have a few tile questions:

1.) Will 1/8" thick polymer-modified thinset adhesive (for wet installations) hold those large tiles to my walls?

2.) How wide should I make my grout lines for these large tiles?

3.) Do I need to do anything special with the floor? Sub floor is currently 3/4" OSB on joists @ 16" o.c. (floor is solid) I plan to cover the OSB with thinset mortor, 1/4" thick cement backer board, and tape the joints with fiberglass tape and mud.

Any insight is much appreciated.

Thanks,

Wayne
(Jack of all trades in Chicago, IL)

Polymer modified thinset is the best choice and will hold the tile fine.
I like 1/8 to 3/16th inch joints. It depends on the quality of the tile.
If your floor is "solid" you should be fine... it sounds like your on the right track.. some folks would flip about the OSB though.

Regards
Mark Lauzon
www.stoneadvice.com
Slab fabricator heaven