Roofing in San Francisco, CA

Serving San Francisco and Surrounding Areas

Roof Problems San Francisco Homeowners Actually Face

Fog rolls in most mornings and Pacific storms drop weeks of rain between November and March, so a San Francisco roof stays damp far longer than it should.

The housing stock compounds it: flat and low-pitch roofs on Victorian and Edwardian buildings, parapets that trap water behind scuppers, and original wood sheathing patched for decades.

• Ponding water on flat roofs — a clogged scupper or downspout lets water sit on a built-up roof or membrane until it delaminates and seeps through the roof deck.
• Granule loss on asphalt shingles — UV and salt air erode three-tab and architectural shingle surfaces, exposing asphalt and letting water wick down into the felt, tar paper, and wood decking.
• Flashing failures along the roofline — step flashing, counter-flashing, chimney flashing, and a cracked pipe boot are where most leaks begin, usually at a valley or where a dormer meets the field course.
• Rot and decay at the fascia and eave — water spilling off a clogged gutter soaks the fascia, soffit, and drip edge, and the rot travels into rafters and truss tails before it ever shows indoors.
• Sagging roof planes and ridge lines — a settled rafter or a wet purlin and batten assembly reads as a dipped roofline, and ignoring it turns a repair into structural framing work.
• Condensation and poor ventilation — a blocked soffit vent or dead attic fan holds moisture in the insulation, which flakes paint, spalls the sheathing, and grows mold on the underside of the roof deck.
• Wind uplift on hillside and mansard roofs — exposed fasteners, overdriven nails, and missing sealant at the rake and verge let winter gusts peel the overhang and awning edges loose.