Hanging drywall 24" OC on the ceiling?

[Cryptic1911]

hey guys, in my garage addition, the upstairs has scissor trusses for a vaulted ceiling, and they are spaced 24" on center. I hadn't thought much of it at the time, but now I'm wondering how the drywall process is going to go. Is 5/8" drywall strong enough to span 24"? I know they make some 1/2" sag resistant stuff, but it doesnt look like they make it in 5/8.. and I don't really want 1/2" anyways. Am I going to have to run blocks inbetween the trusses to have something to screw into in the middle of that span? Basically, am I better off with the 5/8" regular, or the 1/2" sag resistant? I'm guessing 5/8 is probably cheaper since its more readily available


also, when considering insulation, if I hang 24" r38 up there and staple it, am I going to have an issue with it hanging down a little when I put the drywall up? I mean is it going to just push up in there when I screw the drywall in? or is it going to have enough resistance to bow the drywall?

 

[wbrian63]

5/8" will span 24" no problem.

If the r38 is going into a stud bay where it is tightly compressed, it will make the installation of the sheetrock harder, but it shouldn't cause it to bow. Once the batt is compressed, it actually doesn't have much outward push to it. The issue will be if it pushes out hard enough to keep the sheetrock from touching the truss when you are attempting to install it.

Sheetrock must be firm against the substrate it's being attached to BEFORE the screws are driven in. Without that firm backing, almost as soon as the head of the screw reaches proper depth in the face paper, the back will blow out.

If you're concerned about this, consider using strapping across the trusses and turning the sheetrock 90 degrees (long edge of the rock should always go perpendicular to the structure). The strapping can be attached with screws and will hold the insulation in place, then the sheetrock goes up against the strapping. You could also install the strapping 16" on center and remove the issue with the 24" spacing you have now. Plus a 1x4" strap gives you a 3-1/2" mounting surface vs the 1-1/2" edge of a truss.

 

[Cryptic1911]

ah, not a bad idea.. you're talking about doing this?

that might be the a good way to solve my concerns, only issue is that I'd have to drop all my recessed lights down to where the new ceiling height would be. Thanks for the info though.. I might just do it

 

[Kevin54]

Drywall is hung on 24" spans on ceiling joist everyday. Just make sure you run the sheets longways across the joist and not longways from wall to peak.

 

[Cryptic1911]

hm, wasn't aware of that.. had a couple people telling me that it would sag for sure if we used 1/2" abut werent sure about 5/8

 

[Abbott]

5/8" on 24" centers is no problem.

 

[rwhite692]

5/8" ..........ftw!

 

[Gary S]

Most houses have 24" on center ceilings and use 1/2" drywall. They last 50 years and longer without sagging.

 

[rockchucker]

5/8" Rock 24" OC all day long. 1/2" 24" OC will sag on the lid for sure.

You probably MUST use 5/8 "X" type Fire Rock on the lid to be within code though.

If you are worried about the Insulation then hang the Rock first and the Insulation second if possible. re read....Can't really do that unless you blow in the insulation. Just make sure your Insulation installation is superb as to not have too much sag to make up for while hanging the Drywall.


Don't kill yourself and just rent a Hoist for hanging the Lid. Sure you can heave those sheets up there but holding them while finger f@#king around for a screw and drill can **** sometimes. Save your back.


Also save yourself some Tapin' and Muddin' and go with 12' x 4' Sheets of Rock. Not too hard to install with a Hoist. It is getting them moved around that is the pain.


http://www.drywallhoists.com/us/products/RLP9000.asp?gclid=COWCwsLItKICFRJDgwod6z4E6A


Good luck with the project.


I personally would go buy one of these bad boys from Senco to finish off all of the screwing if it is a large project. No more picking for screws. Load up a strip and point and shoot. Saves time in the long run but is a little more expensive for the fasteners.


http://www.cposenco.com/products/3p0001r.html


Have 2 of them and love them. They can be a little touchy but you get used to them. 2 guys with 2 guns can get a whole lot of Rock screwed off for sure...

 

[mikeyr]

mine was done with 1/2 on 24" centers, the drywaller said it would not sag and would be fine. I have known him for 10+ years and he has always done great work so I trusted him. Besides with those tall ceilings I hated the idea of him getting 5/8" up there.

So far so good but only 6 months so not a real test except to say that a 30+ year drywaller said it would be fine.

 

[1984GMC]

I got a deal on 30 sheets of 1/2 4x12 for mine So that's what I'm gonna use.

 

[Gary S]

mine was done with 1/2 on 24" centers, the drywaller said it would not sag and would be fine. I have known him for 10+ years and he has always done great work so I trusted him. Besides with those tall ceilings I hated the idea of him getting 5/8" up there.

So far so good but only 6 months so not a real test except to say that a 30+ year drywaller said it would be fine.

I don't think you have anything to worry about. My house is 58 years old and has 1/2" sheetrock on 24" rafters with no sag.

 

[jkeyser14]

My friends garage has 1/2" drywall on 24" centers and it's horribly sagged and has broken in a few places where it sagged too far. I really think it depends on temperature cycles, humidity, etc.

 

[Cryptic1911]

hmm, yeah I'd probably be ok with 1/2, but I'm going to go with 5/8 type x for the whole place anyways.. thats why I was leaning towards the 5/8ths for the ceiling too.

Thanks for the input guys

 

[Busted_Knuckles]

If you check with a gypsum wholesaler, somebody makes a 1/2" ceiling specific panel in 8 and 12 foot sections, for 24" centers, its reinforced and is designed specifically not to sag. Ive never worked with the stuff, just know its out there, but dont know who makes it.