QUESTIONHow do I find the Standards to verify if my Tile Installer properly Installed my Tile Backer Board?
ANSWERANSWER - There is an ANSI A108.11 for the installation of cementitious backer board. Technically Hardibacker board is a fiber cement board, but the installation methods are the same.
The ANSI standards are recommendations and they always say that the manufacturers' directions supersede their recommendations. So you should look at the Hardibacker data sheet from the manufacturer for their installation recommendations.
Generally the recommendation is to adhere the backer board to the wood subfloor with an appropriate thin-set mortar (ANSI A118.11 thin-set) and to screw or nail the backer board into the plywood subfloor. The backer board should be installed in a staggered pattern and fastened every 8" in each direction. Wet areas should have some sort of waterproofing over properly sloped to drain surfaces for floors, and moisture barriers on walls.
The only way to determine if the installation was done correctly is to intrusively remove and document sections to see how it was constructed. Www.CTaSC.com does those types of forensic investigations, but it may or may not be practical for you to utilize our services as it can cost $3,000 or more for an inspection.