Drywall Span Question

[MiGarage]

This is my first post i am starting my garage renovation now. It is a 24x24 foot older garage. I am assuming 50's or 60's. It had very low ceiling joist/rafter ties which limited my ceiling options. I raised them up about a foot which is still under the 1/3 limit rule. They are every 32 ins and there is about 8 of them when there was only 4 before. My question is for drywall. I am planning to put 2x4s that run every 24 in perpendicular to the ceiling joists. The largets span would be 32"x24" for the drywall. would the sag resistant light weight 1/2" drywall handle this or would i need to use 5/8". Only concern for 5/8" is weight and the raised ceiling joists conflicting. Has anyone done this? Or can lend any advice?

 

[pattenp]

Is the garage attached or detached? Depending on your location, if attached fire code will most likely require 5/8".

 

[MiGarage]

it is detatched. I don't have a problem using 5/8's... after raisng the joist the span is 18x24 so 13.5 sheets. If a standard sheet of 5/8 weighs 70 pounds thats 950 pounds, which is what concerns me on the raised joists.

 

[Falcon67]

Then consider 7/16" OSB, which is about 55 lbs/sheet. FWIW. 1/2" drywall doesn't like 24" OC support.

 

[sands35]

For ceilings, 5/8 is more sag resistant that 1/2". I don't know if that is a code requirement for detached though. Building code also specifies drywall perpendicular to the joists.

 

[MiGarage]

Does anyone think that moving the ceiling joists up would make them unable to hold the weight of 5/8 drywall? would puting the joists every 16" to match rafters help? The i could probably get away with 1/2". Ceiling drywall.

 

[pattenp]

I have 1/2" drywall on my ceiling in my detached garage and the truss are on 24" centers. The ceiling is insulated with batt fiberglass and I see no sagging. I would not use 1/2" drywall on a span greater than 24".