bathroom waterproofing and wall finishes
hey folks,
just about to install walls in new bathroom, and am stumped on the options. Taunton’s bathroom book seems to offer mixed advice on green board, vapor barriers, backerboard etc (e.g. green board good for shower surrounds, but don’t use it where it can get wet, do use it for tile backing but cement board is best, don’t use on ceilings, don’t use with vapor barrier). and we need to have a clean gameplan for the weekend.
we are planning: green board for all walls except for shower which will have hardibacker. Not sure whether to use regular or green drywall for ceiling. We also have plybead sheet for wainscoting, but are not sure whether to install over greenboard or fur out and afix straight to studs–and should the whole thing be wrapped in plastic before hand, or is that going to create condensation pockets behind drywall and mold/rot?
We live in western MD–humid warm summers, cold dry winters.
Thanks
Replies
Use greenboard on the ceiling, as well as behind the beaded plywood or masonite. Glue the bead board to the drywall with paneling adhesive. Good luck.
Tony
Want the best for your tub or shower walls, in terms of a moistureproof membrane?
Forget cement board and use Schluter's Kerdi membrane. Go to the Schluter site and watch the shower installation videos.
Want to see and read tons of stuff about Schluter's Kerdi membrane? Go to the biggest tilesetting forum on the web, over at John Bridge.
A Kerdi drain and the used of the Kerdi membrane on shower walls (and do it atop regular gypboard . . . no reason to use greenboard) is the ONLY way to go. Repeat, ONLY way to go.
Edited 11/26/2005 1:58 pm ET by Stinger
Good advice, but Kurdi might not be immediately available for the weekend. I would use 1/2" cement board on the walls in the shower. Ceiling too, if tile is going up there. 1/4" on the floor if tile is going down there. White or green drywall for the rest of the room. If the tile and grout and caulk is done right, the backer should never get wet. This might be the easier option, whilst still giving many years of service.
thanks for the advice on the kurdi--I will check it out. In the meantime, I am still wondering about stapling plastic behind drywall, and whether green board is better to use for all surfaces in the bathroom.I might have misread the Taunton book, but it seemed to say don't use greenboard on the ceiling, and don't use it with a vapor barrier. Unless someone has something really compelling to say about addiing plastic I think we wont put it in--so that leaves me with the question of green board on walls and ceiling...Thanks!
IMHO, using greenboard is not as important as good waterproofing (read: Shluter), good sealant products and installation, good ventilation. and the use of good primers and paints.
The kind of fan with a humidity sensor that controls on-off is a first choice, after which comes a fan with a timer switch. Size your fan appropriately, and locate in the right spot. Use insulated ducting if it is going through cold attic space, and be wise about the routing of it.
I am partial to the low-sone Panasonic products.
You don't need greenboard anywhere. Use cement board behind tiled areas and white dry wall everywhere else. The rest of the room doesn't need to be waterproof. The drywall gets covered with paint, wallpaper, wainscoting etc.
I think the reason that greenboard is not recommended for ceilings is because the manufacturer wants 5/8" board on the ceiling for 16" joist spacing. If you use regular drywall, 1/2" is ok. This is probably because the greenboard is more prone to sagging. In practice, it's probably not going to be an issue, but when in doubt, follow the manufacturers advice.
Most baths probably don't need greenboard at all, but the ones I've done have 1/2" greenboard on the walls and 1/2" drywall on the ceilings. For the insignificant additional expense of the greenboard, I like my customers to see that I've used the moisture-resistant drywall as additional "insurance" against moisture-related problems.
As for a vapor barrier, it's recommended behind cement backer, but unnecessary (I don't know if it's a bad thing) elsewhere. Except, of course, on exterior walls where you would have only one layer against the insulation.