Roof Maintenance and Repair Guide: Asphalt Shingle Roofing
Part 1: Backed-Out Nails
Lift the existing shingle right above the area where the nails are backing out.
CAUTION: Do not over-lift the existing in-place shingles. Installation is best performed when the temperature is warm enough so the shingles can soften somewhat, so you can work with the shingles without cracking or breaking them.
If the shingle above can be raised enough for you to use a hammer directly on the backed-out nail, re-drive the nail with a hammer directly to the nail head. If the nail is bent, rusted, or too loose to stay firmly in place, remove it completely. Use a new #11 or #12 aluminum, copper, or galvanized steel barbed ring shank roofing nail with 3/8-inch to 7/8-inch diameter heads. New nails should be long enough to penetrate wood plank decks at least 1 inch, or go completely through plywood or OSB decks. Drive the new nail into the shingle in a new location about an inch above the old location. Do not drive the new nail into the old nail hole.
If the shingle above cannot be raised enough to expose the nail head so a hammer can be used, use a flat bar. Place the end of the flat bar on top of the nail head and tap the bar with a hammer to re-drive the nail back into the deck.
Cover the nail heads with a 1-inch wide spot application of industrial grade, asbestos-free roof cement. Apply similar spot applications to the underside of the tab of the lifted shingle which will sit on top of the shingle you were working on. Five spots, one in each corner and the other three spaced evenly across the bottom of the shingle. All spots of roof cement should be applied back about one inch from the edge of the shingle you’re applying it to, so it doesn’t ooze out and become visible when you press the shingle down.
Lower the lifted shingle down onto the shingle beneath, firmly pressing the tabs into the roof cement to adhere the shingle flap.