[tzinho]

Can I use a product like Schluter-KERDI as a vapor barrier in the situation described below?

- Application on top of concrete board in a three-wall shower/tub stall (to be followed later by application of tiles on top of the Schluter-KERDI)

- One wall of this shower/tub stall is an insulated exterior wall on the north-facing side of the house in a cold, dry climate (Colorado)

- There is currently no other vapor barrier installed behind the concrete board, which has been installed directly onto the studs

... or will this cause problems down the road?

The reason I am asking: the standard out here in Colorado seems to be clear plastic vapor barriers BEHIND the concrete board.

I guess the question could also be asked like this: if tile could be applied directly on top of a clear plastic vapor barrier, would these vapor barriers all be installed on top of the concrete board instead of behind it?

Thank you SO MUCH for your assistance. I want a 100% perfect installation, and have been agonizing somewhat over this question.

[JazMan]

Hi,

Vapor barriers are a very confusing subject. Go ahead and install the Kerdi membrane and leave the barrier on the insulation as is. You do not want plastic on the studs behind wall board or concrete board and a surface membrane too. One or the other, not both. But.....the surface membrane is much better cuz it keeps the substrate dry.

I guess the question could also be asked like this: if tile could be applied directly on top of a clear plastic vapor barrier, would these vapor barriers all be installed on top of the concrete board instead of behind it?

So, yes. That's why you've chosen Kerdi, consider it a plastic you can tile over.


Jaz