Backer boards
I live in Alaska/cold wet climate... in the process of redoing a bathroom due to mold problems (created by old construction problems. I have reviewed many of the backer boards and "tilemasterga" videos on YouTube (masterfully detailed but long) and am still wondering what backer board I should use in AK. Then it occurred to me if the problem would be solved by painting Hardie Backer on all sides with a membrane that is used for the joints to solve the mold/moisture problems associated with this otherwise very easy to work with and strong product. I would like your comments on the subject and any others below.... thanks in advance.
I have provided my thoughts, research, and comments from professionals and big box stores...
Dens Shield: pro's - built in moisture & mold barrier, best rated for moisture, includes fiberglass, easy to cut; con's (what I wanted to use but no one sells in Alaska, wonder how it holds up in cold climates)
Durock: pro's - strongest, cement based, fiberglass, water resistant, no swell; con's - edges can crumble when cut, told by contractor that can crack down the road, saw a comment on internet that freeze/warm cycles can lead to this (this is my hesitation for using this)
Permabase: pro's - cement based, fiberglass, edges with fiberglass (less crumble), manufacturer claims lowest water absorption; con's - difficult to cut like all cement boards (if my solution above for hardie backer is not a good one I will likely go with this one or durock)
Wonderboard: pro's - cement, water resistant, fiberglass; con's - everyone states that crumbles
Hardie backer: pro's - strong, easy to cut; con's - no fiberglass so water permeable and requires visqueen (this is the problem I encountered when I took it out it was moldy and crumbled to say the least), contractor comment on internet suggested leaving it outside and watch it delaminate while others swear by it
Green board: pro's - upscale water resistant dry wall; con's - thing of the past, no one recommends as backer board, could use in rest of bathroom