Hardie Backer Board versus Concrete Backer Board in a bathroom?

Question

I am building a shower and replacing the floor in my bathroom. I am going to you use tile for the shower and for the floor. What kind of board should i use for each of them.

Answer 1

Hardy Backer is a concrete backer board. Use 1/2 inch for the floor and 3/8 inch for the walls. Don't worry about filling the gaps with mud. The mastic will do that for you.

Answer 2

You can use either, but in the higher end homes, they tend to use concrete backer board more often. I would use half inch on both the walls and the floor. I wouldn't use anything less than a half on the walls, and you can get away with using 1/4 on the floors, as long as the sub floor isn't wavy, or has a lot of give.

Answer 3

Hi Jason,

I am a fan of PermaBase made by National Gypsum.  It is a cementitious backer unit.  Hardie Backer Board is a fiber cement board.  Both boards (CBU/fiber cement) are approved as a substrate for tile and each has particular qualities (rigidity/forgiveness when flexed, weight, cutting characteristics, the way it reacts to a fastener, porosity) that make it desirable to different installers.  NO tile underlayment adds structural integrity of value.  If you are going to use 1/2" for any type of floor installation, may it be to increase the height of the tile installation to match another adjoining floor covering, not "stiffen" the floor.  Subflooring (joists/plywood) must meet a certain deflection rating for tile and a more stringent one for stone.  As for walls, I know of no board manufacturer that suggests the use of anything other than 1/2".  To find more information about proper shower construction and waterproofing, as well as a tool to check your subflooring, please visit the link below.  Sorry to bombard, but there is a lot of misinformation out there that I myself passed around until properly educated about the ceramic tile industry. :)