LiamM
New Member
hi all
I've read on USG's website that water-resistant gypsum board should not be installed over a vapor retarder in a shower or tub compartment (I'm assuming because of the direct and prolonged water contact) OR when covering with an impervious finish, such as ceramic tile, since it would create a double vapor barrier.
This would seem to imply that it's ok to install greenboard over a vapor retarder - like insulation Kraft facing - when NOT covering with tile, and when NOT in a tub/shower surround. But wouldn't that also create a double vapor barrier?
I've read on USG's website that water-resistant gypsum board should not be installed over a vapor retarder in a shower or tub compartment (I'm assuming because of the direct and prolonged water contact) OR when covering with an impervious finish, such as ceramic tile, since it would create a double vapor barrier.
This would seem to imply that it's ok to install greenboard over a vapor retarder - like insulation Kraft facing - when NOT covering with tile, and when NOT in a tub/shower surround. But wouldn't that also create a double vapor barrier?