screw spacing in ceiling sheetrock

[xrongor]

hey all

im hanging 4' x 8' x 5/8" firex type drywall on my garage ceiling and plan to pump in 8-10" (max) of loose insulation on top of it.

rafters are 24" apart. am i good with 12" screw spacing to hold this up? for a 4x8 sheet this basically puts 5 screws across the width, every 2'. or

25 screws for a whole board.

everything ive read seems to point to 12" spacing, and ive been told it meets code. i just want to make sure before i pump the stuff in and watch my ceiling fall due to the weight.

thx randy

[xrongor]

i forgot to mention. all butt joints have screws spaced at about 8" so theres a few more than 25 screws per board right now...

thx randy

[G Henslee]

I always double screw. In other words I put two screws about 2" apart every 12" or so.

[G Henslee]

It's not overkill to scores of professionals.

[G Henslee]

Maybe some mood lighting and proper music? Oh, and viagra.

[RicodJour]

USG calls for 12" OC screws as maximum spacing. Don't be pennywise. Go with 8" OC. It'll cost you an extra fifteen minutes of your time and a few bucks for the screws.

USG also "strongly" recommends double-nailing ceilings to prevent pops, but does not require double-screwing.

The 5/8" board is maxed out with joist at 24" OC if run perpendicular - if you run it parallel, it's only good for 16" joist spacing. You could go with the 1/2" sag-resistant ceiling board - good for 24" joist spacing either way, and you'd save some of the weight. I'd contact USG and ask their recommendation on which board to use with that much insulation.

R

[xrongor]

sure, i could overkill it.

but is 12" centers 'enough'?

randy

[G Henslee]

In the time you've spent pissn' and moin' you could have had it done. Go 8" if you're concerned and quit fretting over it for krist's sake.

[G Henslee]

PS. -end of subject-

[xrongor]

but why is there such a discrepancy? my local inspector told me that 12" centers is good enough for up to 12" of blown in insulation on top of the

5/8 firex. code normally has some fudge factor built into it... if code says x is enough, why does everyone seem to suggest using x+1?

have you seen an actual failure when someone used 12" spacing?

i mean you don run 10 gauge wire when 12 will do, just to stop from being pennywise... you dont make fishing poles out or rebar either...

randy

[Edwin Pawlowski]

I did that in my 20's, but in my late 50's I don't any more.

[xrongor]

ah man. now i remember why i unsubscribed before.....

come on richard. why 8 inches? you got any info about the structural strength of sheetrock that i cant find on the back of a cereal box?

anybody? buhler? buhler?

randy

[BobK207]

Spanning 24" with 5/8 sheetrock seems a little far.

I'd me more concerned about the 24" than the 12" screw spacing

btw