How to Replace Damaged Roof Shingles

Roof shingles take a beating. Wind tears edges, hail punctures, and simple age makes them curl and crack. The good news is that a few damaged shingles don't mean a new roof—you can fix them yourself in an afternoon with basic tools and materials that cost less than a tank of gas. The trick is knowing where to cut, how hard to nail (not as hard as you think), and when to use roofing cement. Done right, your repair will last as long as the surrounding shingles and nobody will see the seams.

1. Inspect the damage and locate problem shingles. Walk the roof slowly on a mild day when shingles are pliable. Look for curling edges, missing granules, visible cracks, holes, or tabs that are separated from the shingle below. Mark damaged shingles with chalk so you can find them again. Check both the visible side and underneath—water damage often appears as dark spots or soft spots when you press the shingle.
2. Gather tools and safety gear. You'll need a ladder, roofing nails (galvanized, 1.25 inch), roofing cement, a flat pry bar, a hammer, a utility knife, and work gloves. Wear non-slip shoes or boots and pick a day without wind. If your roof is steep (over 8:12 pitch) or you're uncomfortable at height, this is the moment to call a contractor.
3. Position your ladder and reach the damaged shingle. Place the ladder on stable, level ground pointed directly at the shingle you're replacing. Climb slowly, keep three points of contact, and test each rung before transferring your weight. Once on the roof, position yourself so you're not reaching above your head or twisting at the waist. Set your tools within arm's reach so you don't have to back down and up repeatedly.
4. Lift the shingle above the damaged one and remove nails. The shingle above your target shingle is nailed to it. Carefully lift that upper shingle (it's glued down with asphalt, so it takes gentle pressure, not force) and slide your pry bar under the nail heads. Pop each nail straight up—don't twist or you'll tear the shingle. Usually there are four nails per shingle. Work from one side to the other so you don't bend the upper shingle too much.
5. Remove the damaged shingle. Once the nails above are out, lift the damaged shingle gently. It's still cemented down at the bottom edge and on the sides where it overlaps the shingles next to it. Slide a pry bar under the sides and work it free from underneath and both sides simultaneously. Don't yank—patience saves you from tearing adjacent shingles. Once loose, pull it straight toward you and off the roof.
6. Clean the substrate and apply roofing cement. Scrape away old nails, cement chunks, and granules from the bare spot. Use your pry bar or utility knife to get it flat and clean. Apply a thin bead of roofing cement in an L-shape where the new shingle will sit—along the bottom edge and up both sides where it meets adjacent shingles. Don't use too much; a quarter-sized bead per side is enough. The cement seals the edges and prevents water from getting underneath.
7. Nail the new shingle in place. Slide the new shingle into position, aligning the tabs with the shingles below and the sides flush with adjacent shingles. Drive four galvanized nails through the shingle into the roof decking—one near each upper corner and one above each tab cutout. Nail straight in with firm, steady pressure. The nail head should sit flush with the shingle surface, not dented into it. Drive the nails about 1 inch below the adhesive strip (if there is one) or roughly where the upper shingle will cover it.
8. Seal the upper shingle and let cure. Apply a small dab of roofing cement under each upper nail head, then press that shingle down firmly. Apply small dabs of cement along the seams where your new shingle meets the adjacent shingles. Let the cement cure for 24 hours before exposing the roof to rain or walking on it again. Most roofing cements set to touch within 2 hours but full cure takes longer in cool weather.