Required framing for greenboard ceilings
I just had a framing inspection and the inspector told me that I needed to have framing at 16″ oc for the greenboard I put on the bathroom ceilings. The New IRC says that if you use 1/2 Moisture resistant drywall on the ceiling that you need framing at 12″ oc and if you use 5/8″ you need framing at 16″. This dosn’t make any sence to me??? The inspector didn’t know why but he is holding me to it. The fix isn’t a big deal but I would like to let my carpentry students know why. Any info would be helpfull.
bud
Replies
Greenboard sags more easily than standard drywall. Ripples will show if you don't have the supports close enough.
If you ask in Breaktime, you'll get more responses. More builders hang out there.
This is something I've been wondering for years. Most drywall manf. want you to use 12" oc for anything. But they don't write all over their product telling you!
The fastest way to do this is to add some 1x2 strips perpendicular to the joists on 12" centers, and screw the drywall to these. In addition, the 1x's will help sound deadening, be easier to to shim flat, and allow you to use some C'clamps to help hold the drywall in place while fastening.
Put regular drywall up instead.
Coming to you from beautiful Richmond, Va.
I'm not sure where you get the idea to put up regular drywall on the ceiling anywhere in a wet area. I would not allow it in my projects.
Greenboard is the minimym I would put in. Better yet would be something like Densheild but greenboard should be framed 12" OCQuality repairs for your home.
AaronR ConstructionVancouver, Canada
I'm not sure why you're confused- doesn't it make sense that the 5/8" board can span 16". while 1/2" can only span 12"? It's ight in the building code that MR drywall in ceiling applications must be supported at 12" oc.
Beware, also, that sometime very soon (2006 IRC, i believe), it's not going to be allowed as a tile backer in wet applications anymore.
Bob