drywall or sheetmetal ceiling

drmax · 09-03-2012, 10:41 PM

Hello. I have a attached aircraft hangar to my house. It was an engineered trussed 2x4 rafter system, 24" on center. The area is 43'x 37'. Being an aircraft hanger, there is no support coming down to the floor. With this said, I now want to put up a ceiling and insulate. A sheet metal ceiling would be $1500 and light weight. A 5/8 thick drywall ceiling would be around $330 and heavy. At savings money, how would I know if the engineered ceiling could support the drywall and insulation? I have no idea who engineered the ceiling, so I can not ask them. I would imagine/assume it was taken into consideration, that some type of ceiling would be installed, but I'm not about to put up all this drywall, to have something fail. Please advise and thank you....DM

DannyT · 09-04-2012, 11:02 AM

the lightweight drywall available now is 25-30% lighter then regular drywall.

joecaption · 09-04-2012, 11:19 AM

Post a picture.
Most engineered trusses are made to have a clear span and should be fine.

**AtlanticWBConst.** · 09-04-2012, 11:57 AM

Contact the manufacturer of the engineered trusses and inquire with them on their recommendations.

Example: There may be some allowable expansion and deflection of the truss system, that could cause attached drywall to crack.

drmax · 09-04-2012, 09:07 PM

Quote:

Originally Posted by DannyT

the lightweight drywall available now is 25-30% lighter then regular drywall.

I asked Menards about this, and they don't carry light weight in 5/8 only 1/2".
4x12' 5/8's is just over 100 lbs. I can not imagine hanging 3000 lbs of drywall from the ceiling...no way. (i junderstand it's spread over the span, but still) It does have to be 5/8 thick, per my county code. I am interested in a lighter weight 5/8 drywall but appears now i just gotta find it. No on menards. DM

drmax · 09-04-2012, 09:37 PM

found lightweight 4x8x5/8's at HD. 7.73 a sheet. thx for the heads up!

drmax · 09-20-2012, 10:50 PM

Seems I'm having a problem finding the lightweight stuff, so I'll mount the regular stuff. My joists are 24". I'm getting mixed reviews of the screw spacing....anywhere from 12", to 12" and then double screw. Please, give me the skinny on this. I'm pretty sure the length is 1 1/4". Thank you. DM

oodssoo · 09-20-2012, 11:30 PM

Why not acoustic ceiling system?

drmax · 09-20-2012, 11:51 PM

Quote:

Originally Posted by oodssoo

Why not acoustic ceiling system?

hand drive · 09-21-2012, 12:23 AM

Quote:

Originally Posted by drmax

Seems I'm having a problem finding the lightweight stuff, so I'll mount the regular stuff. My joists are 24". I'm getting mixed reviews of the screw spacing....anywhere from 12", to 12" and then double screw. Please, give me the skinny on this. I'm pretty sure the length is 1 1/4". Thank you. DM

for wood application 1 1/2" screws might work better then 1 1/4" for the 5/8 drywall. For 5/8" ceiling drywall screw placement, 4 to 6 inch spacing at the drywall butt seams and 8 to 12 inch spacing in the field.

consider lateral bracing if needed or added blocks at the drywall seams.It is better to do it and anything else needed before covering with drywall...

drmax · 09-21-2012, 02:36 AM

Quote:

Originally Posted by hand drive

for wood application 1 1/2" screws might work better then 1 1/4" for the 5/8 drywall. For 5/8" ceiling drywall screw placement, 4 to 6 inch spacing at the drywall butt seams and 8 to 12 inch spacing in the field.

consider lateral bracing if needed or added blocks at the drywall seams.It is better to do it and anything else needed before covering with drywall...

Would you do adhesive on the joist faces? Also, I've read where you're to keep the screws off the edge of the butt end. This does not make sense to me, since the butt end of the sheet of drywall, should end up on 1/2 of the 2x4 joist, and will need fastening. I suppose i'll figure all this out when i get started. I bought 12 2x4x6's for making pieces as I go. I was hoping I didn't need to add anything else between the joists, to further reduce the insulations "lay down" ability.

hand drive · 09-21-2012, 08:17 AM

Quote:

Originally Posted by drmax

Would you do adhesive on the joist faces? Also, I've read where you're to keep the screws off the edge of the butt end. This does not make sense to me, since the butt end of the sheet of drywall, should end up on 1/2 of the 2x4 joist, and will need fastening. I suppose i'll figure all this out when i get started. I bought 12 2x4x6's for making pieces as I go. I was hoping I didn't need to add anything else between the joists, to further reduce the insulations "lay down" ability.

I've always angled the screws some at the butt seams so the screw head is further onto the piece but also having a solid grab into the framing member, another good reason to use the 1 1/2". If you grab a hold of the trusses and shake them do they move around any? That is the reason I mention bracing, the roof part of the truss is braced by roofing application so the bottom cords of the trusses could be free to move around. It will help if they are as stable as possible for drywall application. What size insulation are you using?

drmax · 09-21-2012, 09:15 AM

Quote:

Originally Posted by hand drive

I've always angled the screws some at the butt seams so the screw head is further onto the piece but also having a solid grab into the framing member, another good reason to use the 1 1/2". If you grab a hold of the trusses and shake them do they move around any? That is the reason I mention bracing, the roof part of the truss is braced by roofing application so the bottom cords of the trusses could be free to move around. It will help if they are as stable as possible for drywall application. What size insulation are you using?

r-13 rolls....24" wide. that will get it to the top of rafter, then either roll out r-19 on top of that, or possibly blow. I was considering you PL-100 adhesive for extra strength, but there's nearly $200 worth of that stuff.
I have not tried to shake the trusses. I will try that and can put in some bracing if needed.