Lucky for me, I’m doing a full second story add (about 1200 sq ft) 3 blocks from my house. The lunch options really open up when you can go home every day! Anyway, as we are trying to make the addition as energy efficient as possible, and it’s basically new construction from the first floor up, we’re taking our first stab at full 2′ o.c. framing (studs running in line with the rafters of course).
The ceiling is mostly stick framed and vaulted, with the exception of one section of parallel cord trusses. The walls are 2 x 6. It will be a hot roof assembly with closed cell foam, and the walls will be foam as well.
We are planning on using 5/8″ rock on the ceiling and on one wall that is required to be a firewall due to proximity to the property line. What are the pros & cons of 5/8″ rock on the ceiling vs. 1/2″ ceiling board? We are hanging it ourselves, but we will be using a lift.
How about the walls? I’ve never framed walls at 2′ o.c., is 1/2″ OK?
If it matters, everything was framed with KD premium lumber (very straight studs), and we have kept everything very dry during the frame up.
Replies
1/2" is acceptable, but is known to deflect more noticeably on 24" centers. 5/8" is a nice upgrade and really makes the wall and ceiling more rigid. In the ceiling think warm ceiling, increased deflection = sagging bays. Not bad, just noticeable if you are looking for it.
Edited 12/4/2008 8:45 am ET by OSUATIinstructor
I would use 5/8's all around simply because 1/2 can easily deflect with someone leaning on it when framing is 2' OC.
Bruce
Had any experience with ToughRock ceiling board? It's 1/2" but supposedly better for ceilings than regular 1/2".I've spec'd it for my new build, but flying blind here. Will be doing 24" o.c. all around.Edited 12/6/2008 7:03 am ET by MtnBoy
Edited 12/6/2008 7:04 am ET by MtnBoy
remember the addl thickness when you order doors & windows otherwise you'll get good at jamb extensions.
Good point, I completely forgot about the windows...the're supposed to be here on Monday...and of course they are all 6 9/16". Oh well, 1/2" it is then. Would using 1/2" ceiling board on the walls help at all with the potential deflection issues?
What's wrong with still going the 5/8 way? 1/8 or so extensions are easy to make use it for another reveal between the jamb and casing and it makes for a pretty good look. I would stay away from 1/2 on 2' centers and wouldn't compromise just because you don't want to make extensions
what Danno said. I'd hate to find out the hard way about the 1/2 ceiling rock working or not. 24ocs needs 5/8. Like I said, you're going to get good at doing the extensions.
5/8" it is then...the extensions are really no big deal. Since I deal almost exclusively in old houses, I'm constantly having to make custom jamb extensions when we put new window units in old walls. Often they need to be tapered rips with some additional fine tuning in place with a hand planer, so I guess some consistant 1/8" rips will seem pretty easy by comparison...It's a shame I hadn't thought enough about it earlier...with the Marvin windows we're putting in I could have had the jambs made any dimension I wanted.Thanks all.
use 5/8 everythwere. its stronger, denser and span rated. i do tons of doors and windows and always stock 1/8, 1/4, 3/8, 1/2, 5/8 and 3/4 rips on my trailer and stack them if needed. i find myself holding the windows out a bit sometimes anyway, especially to cover paint lines on ext. brick and such.
i would never trust 1/2 on 2'oc, one stray elbow when moving a door frame and more taping...Dan Lynn, Dan Lynn Construction, Joliet, IL
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