Garage ceiling insulation

goodheat | Posted in Green Building Techniques on July 9, 2016 10:11am

Hello, I’m insulating my garage ceiling with 2″ xps with all the seams filled with great stuff and 2×4 sleepers to attach the drywall to. The screws that I am using are GRK Fastener #12 x 5-5/8 that I purchased from Lowes. The package states Avg. ultimate load is for #12 is 1,210 sheer test. Will these screws hold the 2 x 4 and the 5/8 drywall with 1 screw driven into each floor joist every 16″ ? How do these screw compare to Fasten Master HeadLok?

Thanks
Scott

Answer

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Replies

user-2310254 | Jul 09, 2016 05:58pm | #1
Scott. Where are you located? Is there conditioned space over the garage? I know I'm not answering your question, but more information about your project would be helpful.
user-6184358 | Jul 09, 2016 11:44pm | #2
The Value you want for the screws is the pullout value - from the FastenMaster Website in the ICC report the HeadLok screw in douglas fir in edge grain good for 390 lbs for 2" of penetration into the main member- http://www.fastenmaster.com/resources.html click on FlatLOK TER 1501-08 (ASD) look at table #8
The GKR website and ICC report is not easily understood as they provide pull thru numbers for OAK, not framing limber.
goodheat | Jul 09, 2016 11:47pm | #3
Zone 5 and there is a room above the the garage
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GBA Editor

Martin Holladay | Jul 10, 2016 04:09am | #4
Scott,
I'm not an engineer, but my instincts tell me that you'll be OK with a screw every 24 inches. I'm basing that judgment on recommendations for furring strips on walls, not ceilings -- based on the idea that the drywall weighs less than many types of siding. (I know, gravity operates differently on a ceiling than on a wall -- but I'm using my instincts here.)

For more information on this topic, see Fastening Furring Strips to a Foam-Sheathed Wall.
Expert Member

MALCOLM TAYLOR | Jul 10, 2016 10:59am | #5
Scott,
They will hold the insulation and drywall with a huge margin of redundancy. The reason for all the worry about similar installations on walls is the possibility of the shaft of the screw slumping a bit. On a ceiling there is no such movement.
As Tim said, the GRKs pullout is somewhere around 400 lbs. Their loading, with the floor bays filled with cellulose, strapping and drywall, is probably at the most 6 lbs each