For a bathroom project, I plan to use backer board on walls and floor. Backer board used on walls will go directly against studs and for the floor it will lay on top of 3/4" ply. My local warehouse store carries backerboard only in 5/16" and 1/2" sizes. Due to size restrictions and other issues, I'd prefer to use 5/16" for everything. Can anyone see a reason why this would be a problem?
A DIY book I was reading said the floor should be at least 1 1/8" thick using backerboard no less than 3/8" (over ply). I'll be 1 1/16" total thick with only 5/16" backer board. 1/16" isn't anything to worry about, right?
Thanks for your opinion.