Roof Inspection, Flashing Repair, and Shingle Replacement

Ground-Level Inspection

Walk around the house and look at the roof with binoculars. Check for: missing or curling shingles, visible gaps in flashing around chimneys and vents, sagging sections of the ridge line, and debris accumulation in valleys.

Look in the gutters for granule accumulation. Asphalt shingles shed granules as they age — a handful after a storm is normal, but thick deposits in the gutter indicate the shingles are nearing end of life.

Check the attic if accessible. Look for daylight coming through the sheathing, water stains on rafters or sheathing, and damp insulation. A leak shows in the attic before it shows on the ceiling below.

After storms with hail or high winds, look for dents in metal flashing, missing shingles, and debris impact marks. File an insurance claim promptly if you find storm damage — most policies have time limits.

Replacing Damaged Shingles

Work on a dry, warm day. Cold shingles crack when bent. Hot shingles tear under foot traffic. 50-70°F is the sweet spot.

Lift the edges of the surrounding shingles to expose the nails holding the damaged shingle. Use a flat pry bar to pull the nails. Slide the old shingle out.

Slide the new shingle into position, aligning it with the surrounding courses. Nail it with four roofing nails: one inch from each edge and just above the adhesive strip. Press the overlapping shingles down over the nail heads.

Apply a dab of roofing cement under the edges of the new shingle and the surrounding shingles that were lifted. This reseals the adhesive bond that was broken during the repair.

Match the replacement shingle to the existing roof. Shingles darken with age and UV exposure. New shingles from the same manufacturer and color line will still look different for 6-12 months until they weather to match.

Flashing Repair

Flashing is sheet metal installed where the roof meets a vertical surface (chimney, wall, vent pipe) or where two roof planes meet (valleys). It directs water over the shingle surface rather than letting it seep underneath.

Step flashing (L-shaped pieces along a chimney or wall): if one piece has slipped, push it back into position and seal the top edge with roofing cement. If it is corroded through, replace it — slide out the old piece, slide the new one in, and nail through the vertical leg into the wall sheathing.

Vent pipe boots (the rubber collar around plumbing vent pipes): these crack from UV exposure after 10-15 years. When the rubber splits, water runs down the pipe into the attic. Replace the entire boot — pry up the surrounding shingles, pull the old boot, slide the new one over the pipe, and reshingle around it.

Valley flashing: open valleys have exposed metal. If a seam has opened, clean it and seal with roofing cement and a patch of matching metal. Closed valleys (shingled over) are harder — water infiltration in a closed valley usually means re-shingling the valley entirely.

Common Problems and Their Causes

Ice dams: ice forms at the eaves, backing up water under the shingles. Cause: heat escaping through the roof melts snow that refreezes at the cold eaves. Fix: improve attic insulation and ventilation, not heat cables or ice dam removal products (these treat symptoms).

Moss and algae: green or black growth on the shingles. Holds moisture against the roof surface and can lift shingle edges. Remove with a 50/50 bleach and water solution sprayed on and rinsed off (do not pressure wash — it strips granules). Install zinc or copper strips along the ridge to prevent regrowth.

Ponding water on flat or low-slope roofs: standing water accelerates membrane degradation. Check drains and scuppers for blockages. If the roof structure has sagged, adding a cricket or tapered insulation to direct water to drains is the proper fix.

Safety on the Roof

Falls from residential roofs are a leading cause of homeowner injury. If you go on the roof: wear rubber-soled shoes, work on a dry day, and use a harness tied to a ridge anchor or a solid anchor point on the opposite side of the roof.

Never walk on a wet, frosty, or moss-covered roof. The surface is as slippery as ice.

Extension ladders should extend at least 3 feet above the roof edge and be set at a 4:1 angle (base 1 foot out for every 4 feet of height). Secure the base and have someone hold the ladder while you transition onto the roof.

For steep roofs (8:12 pitch and above), professional roofers use roof jacks and planks to create a working platform. This is not standard homeowner equipment — hire a professional for steep roof work.

When to Hire a Roofer

Large areas of missing or damaged shingles (more than a few). Any structural issue (sagging ridge, spongy sheathing). Flashing work on multi-story chimneys. Full valley re-shingling. Any work on steep roofs. Any work on tile, slate, or metal roofing — these require specialized skills and different tools than asphalt shingles.

Get multiple quotes. A reputable roofer will inspect from the roof (not just the ground), provide a written estimate with materials and labor itemized, and pull permits for full replacement jobs.

Frequently Asked Questions