What Size Roofing Nails For 1/2 Plywood

Expert Member

Armando Cobo | May fifteen, 2012 11:16pm | #1

I'chiliad sure your roofing manufacturer would accept available downloads of their installation manuals. As I read a CertainTeed shingle installation manual (chapter 8), does non mention a word on cut off any nails.
"Nail shanks must be long enough to penetrate the roofing then go ¾" into solid wood, plywood or not-veneer wood decking, or through the thickness of the decking, whichever is less."

GBA Editor

Martin Holladay | May 16, 2012 04:36am | #2

David,
I disagree with your estimation. Every time I read a requirement that says that 3/four inch is "the minimum penetration of a roofing nail into roof sheathing," I interpret that to mean that the nail needs roof capsule that is at least 3/4 inch thick, and that the nail must stick out the dorsum side of the sheathing at least a tiny niggling flake.

So, I think y'all need 3/4 inch plywood or solid board roof sheathing.

Neb Rose | May 16, 2012 08:25am | #three

Some time ago (a hundred years?) roofing nails did not penetrate the deck. Thicker decks and shorter nails. I call up the difficulty twirling those i" roofing nails. This had 2 benefits: one) a neater looking attic, and two) no condensing or frosting points. The downside, I retrieve, is that the shrink-great process in wood that "walks" the nail out of the deck tin can happen more easily.

I've had historic jobs where I requested clipping the protruding nails with a commodities cutter.

David Johnson | May 16, 2012 08:53am | #4

Simply for clarification: The roof is done, and the one/two" OSB assumption was a worst case. If the sheathing is actually 3/4", then I should be able to cut the nails off affluent per the specification. The question was whether whatever cutting of the nails would cause a trouble as long equally I complied with the 3/4" in the original specification.

GBA Editor

Martin Holladay | May xvi, 2012 09:11am | #5

David,
I'm confused. If the roof is washed, you should be able to respond the question of whether the building has i/2-inch roof sheathing or three/4-inch roof sheathing.

David Johnson | May xvi, 2012 x:17am | #half dozen

The question is whether cutting the nails will be a problem equally long as I leave >=3/iv" penetration after doing so.

Proficient Member

Armando Cobo | May sixteen, 2012 10:43am | #7

David,
"When fasteners do non penetrate the deck at least 3/4" or all the way through thinner panels, the likelihood of nails backing out, or coming loose, is very loftier" Minimum nailing base should be iii/8" plywood or vii/16" OSB… If you are worried well-nigh condensation on the nails, then you should install a coach with rigid foam in the middle.
What does your shingle manufacturer's installation instructions say? What shingles are you installing?

GBA Editor

Martin Holladay | May 16, 2012 10:51am | #viii

Armando,
If the transmission calls for a "minimum penetration of a roofing nail into roof sheathing" of iii/4 inch, why do you write that "Minimum nailing base should be 3/viii" plywood"?

Good Member

Armando Cobo | May 16, 2012 01:54pm | #9

Martin,
If you are using roof sheathing that is three/four" or thicker, so the nail must penetrate three/4" min. into the sheathing. If you are using an canonical roof sheathing that is less than 3/4", like 7/16 OSB or three/8" plywood, then the nail must become all the way through. They do specify the shank to be 11-12 gauge, the head diameter to be st least 3/viii", but no specs on how long the shaft needs to exist after passes through a 7/sixteen" or 3/8" capsule.
I do recall it can be confusing the way their installation manual is written. I've contacted CertainTeed tech support and asked if they could answer this thread, hopefully they do.