Kerdi Membrane Question/ Vapor barrier

wrea398

I am rebuilding my bathroom and just finished the Hardibacker on the floor and installled the tub. Its a standard 30/60/30 (3) wall surround and the tub is on an outside wall. I replaced the wall insulation and was getting ready to start the Hardibacker on the walls. I am using Kerdi membrane on the tub surround walls. I have read soooo many opinions online about a NOT USING the plastic vapor barrier or roofing felt UNDER A WALL WITH KEDRI MEMBRANE as it will cause vapor traps.

I just watched Holmes on Homes tonight as he was doing the exact same remodel using Kerdi. He DID INSTALL 6 MIL PLASTIC under the backer board on the studs and applied Kedri membrane to the inside of the backerboard. This is just what we ARE NOT suppose to do per all the online opinions I have read. Mike Holmes is suppose to be todays "premier contractor" who always does it right. Where is the truth? I am ready to hang the hardi on the walls and dont want any issues in the future. Opinions?

NASCAR9

Have you been to www.johnbridge.com? This site is deticated to tile with many folks using kerdi.

Barnettdeck

Use plastic on exterior walls only. Better not to use it so you can glue and screw your Hardi board.
RB
BS physics, Master carpenter