I am installing a Gerber back outlet toilet in a basement. The flange will be flush against the drywall behind the toilet. Instead of affixing the flange directly to the drywall, should I cover that area of the drywall with a material that is waterproof (such as tile), and then attach the flange to the waterproof material. Or is it O.K. to simply attach it to the greenboard. Thanks!!
WHY “Gerber”? Have you checked out Crane? oh well to each his /her own I guess.
About the installation, the better codes say to install on NON ASORBENT materials ( to me this sounds like tiles huh?) In reality the only time you do get a moisture problem is when the wax seal gives up the ghost,which does happen. Just be very sure of your roughing measurements and how far out your flange will actually stick off the Finished wall. Water resistant sheet rock is anything BUT water resistant. Have you considered wonder board? Have a great week end.