# Roofing nail length...



## MLO (Jan 7, 2006)

I have two layers of 1/2" roof sheathing, making 1" of total sheathing. I will be using a laminated roofing shingle (Malarkey). What is the correct roofing nail length I should use?


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## Ed the Roofer (Jan 27, 2007)

Typically, with one layer of plywood deck sheathing, you ar supposed to penetrate all the way through and have a minimum of 1/4" penetration through and past the bottom side of the decking.

With solid plank board decking, a full 1" embeddment into, but without penetrating the plank boards is recommended.

What you have is a hybrid between the 2 recommendations. I would venture to speculate that a full 1" into the double layer 1/2" decking would be suitable, but for sake of leaning to be overly cautious, I would =use 1 1/2" nails minimum.

Ed


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## the roofing god (Aug 2, 2007)

I would be concerned w/expansion/contraction between 2 layers of plywood causing nails to pop out and through the shingles,technically the nail has to imbed 3/8ths of an inch ,but I would be more comfortable w/1 3/4" nails


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## the roofing god (Aug 2, 2007)

when you sheathe over heavy decking 34"t&g.or 5/4" skip sheathing the lower decking doesn`t have the same give as plywood does


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## roofboy (Jan 18, 2007)

Hello,

I have installed many squares of Malarkey shingles. They require a minimum 1/4" penetration through the sheeting, it states that on the bundle wrappers. 1 1/2" should be sufficient. 1" of sheeting,1/4" thickness of two layers of shingles, leaves 1/4" of penetration.:thumbsup: 

Keith


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## the roofing god (Aug 2, 2007)

GAF READS 3/8THS,AND THE POINT IS W/2 LAYERS OF PLYWOOD THE LOWER WOULD MOVE AGAINST THE UPPER AND CAUSE NAILPOPS UNLESS YOU IMBED INTO THE LOWER LAYER THE REQUIRED AMT,AND EVEN THEN W/DECK MOVEMENT during temperature extremes ,I wouldn`t care for it:no:


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