Walls and Ceilings - ceiling drywall min joist span

Hi,

I recently removed a layer of dryall (1/2 inch) and wood (1 inch) from the ceiling exposing the joists. The joists vary in span, from 30 inches to 10 in some spots). I want to put drywall up now, but i assume 5/8 drywall won't span well over 30 inches. My plan is to run some strapping (1x4's or something) every 18 inches along the joists and then attach the drywall to that. Does that seem like a reasonable idea? Is it too far away, too close? Should i use 1/2 inch drywall?

Thanks!!!

Bob

Hey Bob. What you are suggesting is right on. With varying joisting, you are looking for trouble with 30". Place your strapping at 16 inches on center and make sure it is running true. I would start by measuring from one wall to the center of the room at each end, snap a line, and install from this center point to the wall. Do the same with the sheetrock. You will find the sheetrock will be considerably easier to install, since you will have increased your screwing surface from 1 1/2" to 3 1/2" -- nice. Good luck with the project.

I'd suggest running the 1"x4"s every 16" on center and then using 1/2" drywall will be sufficient, provided it is acceptable with your local bldg code if one is present in your location. Good luck with your project.

awsome, this is what i'll do then! i'll check my building code, but why is 5/8 inch drywall typically recommended for ceilings? Sound? Fire? Not sagging?

THanks again, u guys rock!
Bob

Sound deadening and sagging, I suppose. But in a 2000 degree flashover 1/8" of sheetrock is comedic. You are placing the sheetrock on 16oc, so sagging won't be a problem with 1/2" rock. Sound deadening??? Use insulation.