1 2 is too small.
Roofing nail length.
Use the 3 4 and just 6 nail the shingles.
Roofing nails minimum 12 gage 0 105 inch 3 mm shank with a minimum 3 8 inch diameter 9 5 mm head complying with astm f1667 of a length to penetrate through the roofing materials and not less than 3 4 inch 19 1 mm into the roof sheathing.
To determine the nail length you should consider the number of layers of shingles shingle thicknesses underlayment and flashings installed on eaves sidewalls and valleys etc.
Which means it s also acceptable to use 1 roofing nails on asphalt shingles.
We normally use the 7 8 for that type of situation can t remember ever seeing 1 2 though they do all look short as hell.
More than 1 layer of roofing not recommended over 3 8 sheathing.
Planning and executing a good roofing job requires knowledge of every aspect of the job.
Standard lengths are between 1 and 2 inches 2 and 5 centimeters but they are also available at lengths of up to 6 inches 15 centimeters.
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.
Yeah i just assumed he was guessing and it actually was a 3 4 or 7 8 nail.
Where the roof sheathing is less than 3 4 inch 19 1 mm thick the fasteners shall.
Looking at a 2005 tile roof installation manual it looks like the minimum penetration of a roofing nail into roof sheathing was 3 4.
Note that roofing nails come in different sizes lengths and gauges.
The minimum fastener length for an asphalt shingle roof in minnesota is 1 1 4.
So if i assume 1 2 osb sheathing i should be able to cut the nails off with 1 4 still sticking through the sheathing into the attic.
Don t know that i ve ever seen a half inch roofing nail.
The length of the nail is the shank and the shank can also vary.
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.
The thickness of the nail is directly proportional to its length thus the longer the nail the bigger its size.
A 1 nail will fully penetrate through 3 8 roof sheathing but it won t fully penetrate 1 2 sheathing.