Storm damage roof repair in Washington, DC

Summer thunderstorms do most of the harm here. A line of cells crossing from the Shenandoah toward the Chesapeake can bring straight-line gusts that peel up roof edges and snap oak limbs in minutes. Derechos, like the one in June 2012, are rarer but take down trees across whole neighborhoods at once.

Late summer and early fall add the remnants of tropical systems, which drop several inches of rain over a day and test every drain and seam. In winter, nor'easters drive rain and sleet sideways off the ocean for hours, pushing water under flashing that handles straight-down rain without trouble.

Hail is less common than in the Plains, but small to moderate hail does fall in spring and summer storms. On asphalt shingles it knocks off granules and bruises the mat. On older slate it cracks thin pieces, and on aging skylights it can fracture the acrylic dome.

Wind does not push a roof down, it pulls it up. On a low-slope rowhouse roof, suction is strongest at the corners and along the front parapet, where a loose metal edge or an unsealed lap gives the wind something to grab. Once a membrane edge lifts, every gust works it further back.

On shingle roofs, the damage is often a crease line just above the nail strip, where a tab folded back in a gust and laid down again. The shingle looks fine from the yard, but the seal is broken and the mat is cracked. We hand-check tabs on the windward slopes to find these, because they leak and blow off in the next storm.

Slate and metal fail at the fasteners. Corroded nails let go under a gust and a slate slides into the gutter. Standing seam panels with tired clips can rattle and lift at the eave. Our page on repairing older metal roofs covers how we refasten those panels.

Neighborhoods with big canopy, such as Cleveland Park, Takoma and much of Montgomery County, see most of their storm calls from falling limbs. A heavy oak branch can crack rafters even when the roof surface looks only scraped, so we check the framing from inside the attic or top floor before we close anything up.

If a whole tree is on the house, the tree removal comes first, ideally with a crane rather than cutting pieces off the roof. We coordinate with the tree crew, then sister or replace damaged rafters, put down new decking, and rebuild the roof layers to match the rest. Gutters, fascia and soffit damaged by the fall are part of the same repair.

Most homeowner policies cover sudden storm damage, and the adjuster's first question is what the roof looked like right after the event. Our photos, taken before temporary work and with notes on the date and weather, give you that record.

We write a line-item scope for the permanent repair: the square footage of shingle or membrane, the flashing, the decking and any matching issues. When a storm damages part of a slate or shingle roof that cannot be matched, we explain that clearly so the adjuster understands the problem. See our insurance claim help page for more on what we provide.

We never tell you what your policy covers or promise a claim outcome. What we can do is show the adjuster exactly what is broken, meet them on the roof, and answer their technical questions.

A roof can lose its first line of defense and still stay dry for weeks, because underlayment or the layer beneath the membrane holds for a while. When it finally leaks, the damage gets blamed on age rather than the storm, and the claim window may have passed.

If a strong storm passed over your block, look from the ground for shingles in the yard, metal edges sticking up, slates in the gutter and limbs resting on the roof. If you see any of that, or neighbors are getting repairs, a roof check soon after the storm is cheap insurance against a much larger bill later.

Snow load is the other storm risk people forget. A heavy, wet snowfall on a low-slope rowhouse roof can sit for days with drifts piled against the parapets, and when it melts, water backs up under ice at the scupper. After a big snow, look at the top-floor ceilings near the rear wall for a few days.