Roofing nails should penetrate into the roof deck at least how much?

• A. 1 inch
• B. 3/4 inch
• C. 1/2 inch
• D. 5/8 inch

Answer: (B)

Three-quarters of an inch is the minimum embedment for roofing nails. This depth ensures the nail passes through the shingles and into solid wood behind the deck, giving a firm hold against wind uplift and weather. If the nail goes in less than this, it may only grip the thin deck or surface material, which can allow nails to loosen or pull out during wind or temperature changes. The three-quarters-inch standard provides reliable fastening without needing excessive penetration.