[Heritage]

Got into a debate over this at work today when we were boarding up a bathroom.



I say:
You can't put a vapour barrier behind Green board because it creates a double moisture barrier (especially where the boards are getting tiled over).

You shouldn't be putting "safe and sound" insulation in there either, because that might screw up the moisture/air flow behind the boards.



Numb-nuts says:
The exact opposite.
"Safe and sound" the entire bathroom...including ceiling.
Vapour barrier everything...tuch tape all around seams.

So what's the verdict?

[Tom R]

Originally Posted by Heritage

Got into a debate over this at work today when we were boarding up a bathroom.



I say:
You can't put a vapour barrier behind Green board because it creates a double moisture barrier (especially where the boards are getting tiled over).

You are correct, - - it creates a double barrier and can actually lock moisture in.

But, - - you not only shouldn't be tiling over greenboard, - - greenboard isn't even recommended for walls anymore, - - for all it's hype it has failed the test of time miserably.

[reveivl]

What Tom said. Around here you can't even get greenboard anymore. Now it's paperless drywall: nowhere for the mold to grow. Drywall is not a suitable substrate for tile in a wet area, or really anywhere, maybe a backsplash here or there.

[Heritage]

Rreeeallly?

I go Cement in the tub enclosure, but to date I've always used Greenboard on the walls.

Didn't know it was failing. They sell them like hotcakes over here. I must say...this is making my life a little bit harder.

But on a happy note...Numb-nuts is wrong and I'm right...kinda

Good enough for CANADA!

Gracias Amigos!

[Tom R]

Originally Posted by Heritage

Didn't know it was failing. They sell them like hotcakes over here. I must say...this is making my life a little bit harder.

You don't really have to worry about any you have already applied, - - it's not like it's falling off the walls or anything. It just didn't pan out to be as good as it was projected to be . . .

[justinhorton24]

i recently tore out a ladies bathroom and she specifically asked to have green board put back in. well after i finished she told me that i was supposed to have put the green side facing in.

[Tom R]

Originally Posted by justinhorton24

i recently tore out a ladies bathroom and she specifically asked to have green board put back in. well after i finished she told me that i was supposed to have put the green side facing in.

Sheesh!! Should'a told her you would have, but luckily, you noticed the 2 X 4's were installed backwards . . .

[erikb45]

i too heard that greenboard is done. we still usse a purple moisture and mold resistant board commercially

[Tom M]

You cant use green board. Like Reveivl said the moisture not water would would pass through the tile then the board and hit the vapor barrier. Then it would sit there and cause the paper to soak the moisture and grow mold.

Does anyone ever use regular rock in the bath ceiling? I dont do much in the way of baths but 1/2 water resist is not allowed and I cant see use the 5/8 through out a bathroom ceiling.

[kgphoto]

Heck! All I install is 5/8's Rarely ever 1/2 inch.

[dryrocker27]

We were told by a rep. from national gypsum that green board was designed to use in sauna's and steam rooms behind the cedar boards.

Builders started using it in bathrooms to prevent the mold from growing on the ceiling, The problem was that the bathroom was not vented as they are now and the mold was on the paint, not the drywall.

Now that bathrooms are vented, mold is not an issue. In our area, the exhaust fan is connected to the main lighting fixture so it come on any time the light is on.

[dryrocker27]

by the way, we install regular drywall and all bathroom ceilings are painted with semi-gloss.