A cracked, curled, or missing shingle is the smallest roof repair there is, and it is the one most worth doing promptly: one gap in the field lets water straight onto the underlayment. The job needs a handful of tools and under an hour, as long as the damage is limited to a shingle or two and the roof itself is safe to walk on.
Yes, if the damage is one or a few shingles, the slope is low and walkable, the weather is dry and calm, and the decking underneath feels solid. No, if shingles are failing across a slope, the decking sags or feels soft, or the roof is steep, high, or wet — those cases go to a roofer. If the damage is wider than a few shingles but you are not sure how wide is too wide, the repair vs replacement decision guide draws that line.
Loosen the shingle above. Slide the pry bar gently under the shingle overlapping the damaged one and break its adhesive seal. On a warm day the seal gives easily; on a cold day work slowly so the overlapping shingle does not crack.
Pull the nails. Lift the overlapping shingle and pull the nails holding the damaged shingle, then pull the damaged shingle's own nails. Keep the overlapping shingle intact — it goes back down over the new one.
Slide the old shingle out. Work it free from under the overlapping course. If it tears apart, pull the pieces out one at a time rather than forcing the whole sheet.
Slide the new shingle in. Push it up under the overlapping course until it lines up with its neighbors on both sides and at the bottom edge.
Nail it. Drive four roofing nails just above the exposure line — the line where the shingle above will cover them — two on each side of the shingle, clear of the joints below.
Seal the nail heads. Dab roofing cement over each nail head, press the overlapping shingle back down, and add a small dab under its corners if the seal did not re-stick. Keep the cement off the shingle face.
Two things give a repair away: a shingle that sits proud of its neighbors, and joints that line up vertically. Match the bottom edge to the course line, and keep the new shingle's side joints offset from the joints in the courses above and below — water follows a straight joint line downhill. Color match will not be perfect at first; new shingles weather in over months, and a close profile match matters more than an exact shade match on day one.
Use cement sparingly. A dab over each nail head and a small amount under the overlapping shingle's corners is enough; smearing cement across the shingle face traps water and looks bad. No nail heads should stay exposed when you finish — an exposed nail is a future leak. Sweep up granules and old nails from the roof and the ground below before you call the job done.
Wait for the next rain, then check the attic under the repair for drips. A dry attic and a shingle that sits flush mean the job worked. If water still comes in, the entry point was not the shingle — run the roof leak finding guide from the stain backward. If repairs keep multiplying across the roof, price the bigger job with the roof replacement cost guide before patching the same roof again.
You can, but the adhesive seal is brittle when cold, so the overlapping shingle cracks more easily. Pick a warm day when possible, and hand-seal the overlapping shingle with a dab of cement if it does not re-stick on its own.
Match size and profile; color will weather in over months. An exact shade match on day one matters less than a shingle that sits flush and keeps its joints staggered.
Typically four, placed just above the exposure line where the course above covers them. Nails driven through the exposed part of the shingle will leak.
Replace both. If breakage keeps spreading as you work, stop — brittle shingles across a slope mean the field is near the end of its life, and that is a roofer's assessment, not a shingle swap.