Flat & Low-Slope Roof Repair: Costs, Lifespan and Alternatives

Two visits a year: clear valleys and gutters before the rains, then check flashings after the first real storm. In Potrero Hill that matters most because asphalt dries out and sealant pulls back from penetrations years before the field wears through.

Yes. Low-slope sections on Potrero Hill buildings need a membrane or coating system rather than shingle laid flatter than it is rated for, and they are quoted separately from the pitched roof.

Granules in the gutters, curling tabs, repeat stains in the same ceiling after every storm, and soft spots underfoot. In Potrero Hill, asphalt dries out and sealant pulls back from penetrations years before the field wears through.

In inland conditions, composition shingle runs roughly fifteen to twenty-five years, tile underlayment twenty to twenty-five, and coatings seven to fifteen depending on the system.

Potrero Hill sits in San Francisco County and takes long dry heat, hard thermal cycling and rain that arrives in a few concentrated storms. In practice that means asphalt dries out and sealant pulls back from penetrations years before the field wears through.

We start at the flashings, check the deck from inside the attic, and photograph every elevation. On a Potrero Hill property we pay particular attention to dried-out underlayment and attic temperature.

One to three days on a typical Potrero Hill property, depending on size, pitch and how much deck needs replacing. Nothing is left open overnight.

Check the licence, liability cover and workers' compensation, then ask any Potrero Hill contractor what happens if the deck is worse than expected — and get that answer in writing before the covering comes off.