# Green Board over Vapor Barrier?



## bradnailer (Nov 13, 2008)

I'd use cement backer board for the shower area not green board but then that's just my opinion. Green board is water resistant but not water proof.


----------



## Pineapple (Feb 27, 2008)

I'm already somewhat committed to the green board in that I've bought a whole bunch of the stuff! Don't really wanna go through the hassle of borrowing a truck to buy anything different. Right now I'm just debating whether or not I should rip off the poly vapor barrier.


----------



## bradnailer (Nov 13, 2008)

Sorry to be persistant here, but you are just asking for problems using greenboard in a tub/shower enclosure. Borrow a truck and swap some of the greenboard for hardibacker.


----------



## Pineapple (Feb 27, 2008)

Well, I'm not really installing greenboard IN the show enclosure. I've already installed a new fiberglass shower enclosure directly over the stud walls. I now have only to cover a 2' section of wall between the top of the enclosure and the ceiling. Regular drywall hung on these walls for the past 30 years, with the poly vapor barrier behind - no issues. My concern now is, with greenboard, should I remove the poly vapor barrier behind this 2' section surrounding the top perimeter of the enclosure.


----------



## bradnailer (Nov 13, 2008)

Sorry, didn't clearly understand your situation. According to everything I've read, no vapor barrier should be used behind greenboard.


----------



## Pineapple (Feb 27, 2008)

Yeah, that's what I've been reading too. Alright, poly vapor barrier is gone! Now what to do about the foil-faced insulation? I could rip of the foil. But this is an exterior wall, so don't I kind of need some sort of vapor barrier? I'm thinking the foil won't be as bad as the poly when it comes to condensation. Could be wrong though.


----------



## bjbatlanta (Jul 16, 2008)

If you're just worried about that particular area, buy a sheet of Densarmor to hang the top of the tub. It will require a "glaze coat" of joint compound to get it smooth to blend in with the rest of the rock, but being "paperless", mold won't grow on it (according to mfgr's claims). I doubt enough moisture would ever accumulate to actually deteriorate the Densarmor (as attested by the regular board that survived 30 yrs.).


----------

