Getting ready to stock up for summer projects at Menards 17% sale. Some roofing planned, single shingles over 1/2" plywood and OSB. Saw some commercial projects lately with a lot of the nail length hanging down below the OSB. Seems to me the extra length is wasted, hence the question about optimum length. Would 1 1/2" be best for a decent quality shingle and 30 lb. felt?
Joe