What water barrier in tile shower alcove
I’m remodeling a bathroom and have removed a fiberglass alcove tubshower and will replace it with a steel or cast iron tub and tile walls.
Two sides of the alcove are interior walls and the third is an exterior wall. What if any water barrier should I put under the backer board, 6 mil poly, 15 lb felt ?
Would it be better to install water resistant drywall first, then 15 lb felt stapled or tarred on ?, then backerboard ?
Should I put 6 mil poly under the new water resistant drywall
elsewhere in the bathroom walls, ceiling ?What should be on the wall below the tub rim to cover the studs and insulation on the exterior wall and studs on the interior walls ?
I want to do this right, especially with all the mold remediation stuff going on here in Texas. I’ve looked at several sources and get conflicting information.
Thanks very much
Chris
Replies
Hi Chris:
Over the studs, I put 6 mil poly. You can, and I have, use 15 lb felt. The advantage of the poly is that is more flexible and you can see the studs, which is nice for nailing the CBU.
The existence of a vapor or moisture barrier elsewhere in the room is subject to debate and subject to where you might live. In the deep south, where it is hot, those barriers go on the OUTSIDE of the exterior walls. In the midwest, they can no on the INSIDE of exterior walls. There is no need to install them on interior walls inside the bath. There won't be enough moisture to worry about. But I don't see any harm in doing so, however.
As for below the tub. I would just staple poly on the walls and floor, assuming the caulk fails, the poly will catch it.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934