I gutted our bathroom and purchased Hardibacker 500 for the walls around the new bath tub. The tub is a American Standard Americast, the plumber who installed the tub said he wont nail the flange of the tub since it may creek when used. Instead the backer boards will hold the tub when placed over the flange of the tub. The hardiback instructions state to install 1/4 inch from the flange not over it. I will return the Hardibacker and purchase wonder board since they state it can be placed OVER THE FLANGE. Is this correct??
Do I need a Vapor Barrier under the wonderboard or can it be installed over green drywall.