Moisture Resistant Backing

8/26/2020 at 10:05:11 AM

The building codes are always a minimum code so my opinion is no such thing as overkill it is the biggest investment of your life hate to see issues over and extra couple hundred dollars now that can save you thousands later

8/26/2020 at 10:25:13 AM

I always used Kerdi board. But i have also seen plain drywall and drywall with kerdi membrane

8/26/2020 at 11:48:44 AM

Not overkill. It means exactly that. Before installing the tile in a wet area, you must first install a waterproofing membrane over the walls or a waterproof board such as kerdiboard instead of drywall. Cement board alone will still allow water to weep.