1/2" or 5/8" Drywall?

Hi All,

I am about to start putting up the drywall in my basement and have come across an article that has me a little concerned since I have all my drywall delivered and in my basement.
In this article, it is suggested that 5/8" drywall should be used on ceiling if joists are 24" on centre. If 1/2" is used, it will sag and look wavey. My ceiling joists are 12" on centre, but when I framed my bulkheads I layed 2x4 flat and put them 24" on centre.
Can I use 1/2" drywall or will it sag? The widest span is about 4.5'. The others are about 2-3'. Or will I need to get 5/8" drywal?

Thanks

 

Just so we get a good picture, you crossed the 12" joisting with 2x4's laid flat at 24" oc, is that correct? If so, how do you get spans over 4' wide. They should all be 24".

 

Sorry for the confusion. My joists are fine, it is the bulkhead/soffits I am concerned about.

There is one that is 30' and another that is 15' long and are 4.5' wide. The sides are framed with OSB and the flat 2x4s are the cross members that join the two sides. The cross members are flat 2x4s 24" on centre.

 

Part of the problem is that I already have the drywall in my basement and do not have a truck to haul it back and get the other board.

Another option would be to be simply put more cross members in the bulkhead. They would be 12" on centre and would support the regular 1/2" drywall. What do you think?

 

Sometimes you can get by with 1/2" on 24" centers but 16" is better. Adding a strap in the middle would insure there wouldn't be any problems.

 

I agree. Don't take it back, just add a strap in the middle.