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View Full Version : Greenboard on bathroom ceilings yes? no?



Doug Aleshire
10-14-2004, 12:49 AM
It has been mentioned by inspectors that M/R cannot or should not be used on ceilings due to it failing. Specifically the issue appears to be any insulated space above whereby a vapor barrier has been installed. The moisture, if any, stops at the vapor barrier and the backside of the M/R starts to fail, eventually sagging.

I'm getting conflicting information.

Does anyone have good info on it's use for the ceiling within bathrooms and/or recommendations for bathroom ceiling applications? Let's assume for painted and tiled applications.

Thanks in advance

Finnegan
10-14-2004, 12:33 PM
Greenboard is fine, but must be 12" OC rather than 16. I have never had a problem with it. As far as moisture control. A good bathroom paint and exhaust fan should control it. I have never tiled an entire bathroom ceiling. When tiling a shower ceiling I have used cement board, but I am planning on trying GP Tilebacker next. GP makes some other moisture resistant greenboard alternatives you may want to check out.

SteveH
10-16-2004, 09:56 PM
In January, 2006 greenboard will not be certfied as a tile backer board by the International Building Code. What it does is hold the moisture and not allow the gypsum to dry. that's why it sags and that's why the framing on ceilings must be 12" oc.

Doug Aleshire
10-16-2004, 10:14 PM
Steve,

Are there alternatives to ceiling applications? I mean are we suppose to install standard and paint only?

I have seen guys install cement board on ceilings and in fact W/R but I knew about W/R not to be used on exterior walls due to what you described.

The question is if you have an existing or even new structure, almost always they are applying VB to the lid before rock is applied. Is there alternative applications in this case for bathrooms or shower enclosures?

Thanks guys for the feedback

dakota
10-17-2004, 11:54 AM
There are so many varables that is why each application should be based on its own merrits. Here If we have an open bath layout all any one uses is standard rock unless it can be in contact with water. A cieling 2 feet above a faberglass shower unit with properly vented fan, properly painted. I have never had a problem in 30 years. I also do not use green board as a tile backer.

Myron Ferguson
11-10-2004, 08:09 PM
I have never had problems with greenbd on ceilings. I think it is only a vapor barrior if it covered with mastic that holds on tile or painted with a vapor barrior paint such as Bin or even a vinyl wallpaper. But then again all of this is quite often done to regular drywall. This whole vapor barrior thing can be very confusing. Greenboard (moisture resistant drywall) will soon be replaced with mold resistant drywall that should have both the mold and moisture issue covered.