Roofing Nail Length Second Layer

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Roofing nail length second layer.

Use galvanized roofing nails long enough to fully penetrate the sheathing typically 1 1 2 inches for a second roof and 1 3 4 inches for a third. Nails of the proper length should penetrate three fourths of an inch into the roof deck. Place the top of each starter shingle firmly against the bottom of the shingle immediately above it and even with the eaves then nail it into place. More than 1 layer of roofing not recommended over 3 8 sheathing.

Select a length of roofing nails that penetrates completely through the new layer of shingles existing layer and the wood roof deck. If you are putting a layer of asphalt shingles over an existing layer of asphalt shingles on to a 3 4 inch deck or a plank deck then you should be using 1 1 2 inch nails. Wood shakes minimum 3 4 sheathing wood shakes nail type minimum length 18 straight split 5d box 1 3 4 18 and 24 handsplit and resawn 6d box 2. Roofing nails should be long enough to penetrate the roofing material and go 19 mm into osb solid wood plywood or non veneer wood decking or through thickness of decking whichever is less.

If your decking is less than 3 4 inch then a 1 1 2 inch nail will suffice. To determine the nail length you should consider the number of layers of shingles shingle thicknesses underlayment and flashings installed on eaves. Use 1 5 or 1 75 inch roofing nails. Nesting each new row below an existing one keeps the new nails 2 inches below the existing which will help minimize any splitting of the sheathing.

Flashings for re roofing asphalt shingles. However where the roof deck is less than three fourths of an inch thick the nail should be long enough to penetrate fully and extend at least one eighth of an inch through the roof deck.