How to make your roof last longer

Inspect it twice a year, and after storms

The single most valuable habit is simply looking. The National Roofing Contractors Association recommends inspecting a roof at least twice a year, in spring and fall, plus a look after any severe storm with hail, high wind, or heavy snow. You do not have to climb up: a lot is visible from the ground with binoculars, and the attic tells you as much as the surface does.

• From the ground: lifted, curled, cracked, or missing shingles, and granules washing into the gutters.
• At the details: cracked or pulling sealant around flashing, chimneys, vents, and skylights, where most leaks actually start.
• In the attic: water stains, damp insulation, daylight through the roof boards, or a musty smell after rain.

Keep water moving: gutters and drainage

Gutters are part of the roof system. When they clog, water backs up under the lowest courses of shingles and spills over the side onto the fascia, soffit, and siding, rotting wood and finding its way inside. Clean them at least twice a year, more often under heavy tree cover, and make sure downspouts carry water well away from the foundation. In cold climates, clear gutters also reduce the ice dams that force meltwater back up under the shingles.

Ventilate and insulate the attic

Most people never connect their attic to their roof's lifespan, but the two are joined. A hot, poorly ventilated attic bakes the shingles from below, and in winter it drives the melt-and-refreeze cycle that builds ice dams at the eaves. Balanced intake (soffit) and exhaust (ridge) vents let the attic breathe: building code (the IRC) calls for roughly 1 square foot of net free vent area per 150 square feet of attic floor, or 1 per 300 when the venting is balanced high and low and a vapor retarder is in place. Good insulation on the attic floor keeps household heat out of the attic in the first place.

Fix the small things early

• Reseal flashing: the metal and sealant around chimneys, valleys, and vents is the most common leak source. A fresh bead of roofing sealant on a cracked joint costs a few dollars and a few minutes.
• Replace lost shingles promptly: one shingle torn off in a windstorm exposes the underlayment; replace it before the next rain, not after the ceiling stains.
• Clear debris and moss: leaves and pine needles trap moisture, and heavy moss lifts shingle edges and holds water. Clear debris and treat moss before it spreads.
• Trim overhanging branches: limbs scrape granules off in the wind and drop the debris that clogs gutters. Keep them back from the roof.

Know when maintenance has run its course

Upkeep buys years, but no roof lasts forever. When an architectural asphalt roof reaches the top of its 22 to 30 year range, or a 3-tab roof its 15 to 20, maintenance shifts from extending the roof's life to buying time before replacement. At that point, watch for the wider signs of failure and price a replacement rather than chasing leaks. Your town dashboard shows what a new roof costs in your market when the day comes.