Metal roofing
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Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Fast, Reliable Roof Repair Across San Francisco
Roof repair in San Francisco typically costs $450 – $1,400 for most leak and shingle work, with flat roof patches running $600 – $2,200 depending on membrane type and decking condition. We dispatch our own background-checked, uniformed technicians from our San Francisco Bay Area office, not subcontractors. Call (831) 318-8819 and you’ll reach a live person who can schedule a written, line-item estimate before any work starts.

San Francisco roofs fail differently than roofs in the East Bay or down the Peninsula. The marine layer, salt air, and rows of century-old wood-framed Victorians create repair conditions that demand local knowledge. We work the tight lots of the Richmond, the fog-soaked eaves of the Sunset, and the historic overlay districts where a simple patch sometimes needs a structural review. If you own a home in San Francisco, you need a roofer who understands what that means before the first shingle comes off.
Why Brennan Roofing Co San Francisco Is San Francisco’s Preferred Roof Repair Company
We’re an independently owned and operated member of the Garrison Partners family, founded in 2000. That means we answer to a defined, named standard: The Garrison Standard. Written price before any work starts. Background-checked, uniformed technicians on every job. A 365-Day Done Right Promise in writing on every repair and installation. That standard doesn’t change from one San Francisco neighborhood to the next.
Led by Travis Oakley, our crews work San Francisco’s dense residential streets every week. We know which blocks in Noe Valley have limited staging for scaffolding, which Sunset lots can’t fit a debris trailer without blocking a shared driveway, and which North Beach rowhouses need pre-approval before any exterior work goes up. That local knowledge shows up in the quote: we account for access, parking, permit review, and party-wall conditions before the price goes on paper.
Homeowners across San Francisco have trusted us with rowhouse roofs, flat garage decks, and steep Victorian eaves. What they consistently mention is that the price didn’t move at the door and the crew left the site clean. That’s the whole point of The Garrison Code: show up inside the promised window, write the price down, do the work, stand behind it for a full year. You can also read more about our process on our Roof Repair page.
Styles & brands we work with






Flat Roof Repair in San Francisco
Flat Roof Repair here almost always comes down to water pooling and membrane deterioration. Many San Francisco homes have flat or low-slope sections over rear additions, garages, or bay windows. When the fog keeps those surfaces damp for weeks, seams in older torch-down or modified bitumen membranes fail and water finds the decking beneath. A typical flat roof patch in San Francisco runs $600 – $1,200 when we can cut out the damaged section, dry the decking, and weld in new membrane. Full section replacements run $1,200 – $2,200.
Decking Replacement Under Flat Sections
When a flat roof has been leaking for months, the decking below is often rotted well beyond the visible tear. In San Francisco’s older homes, that decking is frequently 1×6 tongue-and-groove fir that soaks up water and delaminates. We cut back until we hit solid wood, replace the rot with new plywood, and only then install the new membrane. That’s the difference between a patch that holds and one that fails again next winter.
Seam and Edge Repairs
Most flat roof failures begin at seams and edges, not in the middle of the field. We inspect every seam, the drip edge, and the flashing at parapet walls and scuppers. On fog-heavy westside lots in the Sunset and Richmond, we usually find the membrane has lifted at the edge where wind-driven fog condensed and worked its way under the material. A seam repair with proper primer and mastic typically runs $350 – $700 before any decking if the structure is sound.
Shingle Roof Repair in San Francisco
Shingle Roof Repair takes different forms across San Francisco. On a preserved Victorian in Haight-Ashbury, it might be matching cedar shingles on a steep pitch with limited staging. On a 1920s Edwardian in Glen Park, it might be replacing a section of architectural composition shingles where moss lifted the seal strip and water got under the course. A typical shingle repair in San Francisco runs $450 – $950. Larger sections involving decking or underlayment run $1,000 – $1,400.
Matching Cedar and Composition Shingles
Matching materials matters on any roof, but it matters more in San Francisco, where many facades are subject to historic district review and a visible mismatch can draw complaints. We keep cedar shingles from manufacturers like GAF and CertainTeed in common widths and exposures, and we’ll weather-match where the existing roof is older or has taken fog-driven oxidation. When we can’t match exactly, we’ll tell you before we start, not after.

Underlayment and Starter Strip Repair
On a windy January morning, our crew repaired a cedar shingle roof in the Outer Sunset where the bottom three courses of shingles had rot from persistent Pacific fog, while the upper roof looked sound. We replaced the rotten decking at the eaves, installed new ice and water shield along the drip edge, and matched the cedar shingles so closely that the neighbor sharing the party wall never noticed the scaffolding. That’s the kind of failure San Francisco throws at you: hidden rot at the starter strip, not obvious damage on the field of the roof.
Trusted Brands We Service in San Francisco
We install and repair materials from GAF, CertainTeed, Owens Corning, IKO, and other leading manufacturer lines. What that means for a San Francisco homeowner is that when we quote a repair, the materials are real, specific, and available locally, not a generic “repair kit” off a truck. If you have a GAF architectural shingle roof in the Sunset or a CertainTeed system on a Richmond rowhouse, we’ll quote the matching product, and we’ll tell you plainly when a different material is the better call for a specific section. Local parts availability means faster turnaround on most repairs.
See the difference
Before
After
Before
After
Before
AfterCommon Roof Repair Problems We See in San Francisco Homes
- Fog-driven rot hidden beneath the starter strip at the eaves. Moisture wicks into the decking and the first visible failure is often a sagging fascia board, not a leak inside the house. By the time you see the sag, the decking is usually gone.
- Wind-driven rain entering through unflashed penetrations on rear elevations. Vent stacks and chimneys on west-facing walls in the Sunset and Richmond take the brunt of Pacific storms, and that’s where we find the most flashing failures.
- Moss and algae from the persistent marine layer lifting architectural shingles on shaded northern slopes. A minor gap becomes a water channel that rots the underlayment, and the repair ends up twice as expensive as it would have been a year earlier.
- Party-wall roof transitions on shared rowhouses. In dense neighborhoods like the Mission and Noe Valley, water often crosses from a neighbor’s roof at the shared wall. The repair has to be coordinated, flashed correctly, and sometimes approved by a structural engineer.
Pricing for Roof Repair in San Francisco, CA
Most roof repairs in San Francisco land between $450 and $1,400. Small flashing repairs or shingle replacement at a single penetration run $350 – $600. Flat roof patches run $600 – $1,200 for typical membrane and decking work. Larger repairs involving decking replacement, underlayment, multiple penetrations, or access from a shared property run $1,200 – $2,200. The biggest cost drivers here are access, permit requirements, and hidden rot. Since many San Francisco homes sit on tight lots with zero side yards, scaffolding and debris handling add cost that a suburban quote never includes. We put every number on paper before any work starts, and the price does not move at the door. Call (831) 318-8819 for a free, written estimate.
We Also Serve Cities Near San Francisco
Beyond San Francisco, our crews regularly handle roof repairs in Daly City, Berkeley, San Bruno, and Albany. If you’re in one of those cities, we bring the same written-pricing standard and the same local attention to marine-climate wear, access constraints, and older wood-framed housing stock. You can learn more about our service area on the Roof Repair in San Francisco page.
Serving San Francisco, CA - Our Local Coverage Area
We’re based in the San Francisco area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Roof Repair in San Francisco
Most small repairs, like replacing a few shingles or patching a flat section under a certain square footage, do not require a building permit in San Francisco. However, work on properties in historic overlay districts or repairs that touch structural decking or party walls often do require review. We’ll tell you plainly whether your repair needs a permit before the quote is final, and we’ll pull it if that’s the right path. Call (831) 318-8819 and we’ll talk through your specific situation.
Yes, in most cases you can repair only the portion of the roof that covers your unit, but San Francisco rowhouses often have shared rafters or concealed void spaces where the roof spans a party wall. That can trigger a structural review before any repair starts. We’ll assess the roof and let you know if the repair can be isolated to your side or if the shared structure needs a closer look. That conversation happens before any work is quoted, not after.
Access has a direct effect on cost. On a typical San Francisco lot with no side yard, the crew may need to carry materials through the house, set scaffolding from a shared walkway, or schedule a debris container that blocks a driveway. Those constraints add time and sometimes require a neighbor’s cooperation. We account for all of that in the written quote so there are no surprises when the crew arrives. Call (831) 318-8819 for an exact number on your roof.
The persistent marine layer keeps the shaded side of a San Francisco roof damp for long stretches, especially on northern and western elevations in the Sunset and Richmond. That moisture promotes moss, algae, and fungal rot in wood decking and cedar shingles, even when the sunny side looks brand new. We inspect the fog-side eaves, starter strips, and fascia boards more carefully than any other part of the roof because that’s where San Francisco roofs actually fail.
Ask whether the quote includes replacing or re-sealing the flashing at every penetration on the affected area, not just the one that leaked. In San Francisco, wind-driven rain pushes water under flashing that looks fine from the ground, and the next storm will find the weak point. A written quote should list the flashing work line by line. Ours does. Call (831) 318-8819 and we’ll walk you through a quote you can actually read.
If you need roof repair in San Francisco, call (831) 318-8819. You’ll speak with a live person, get a written price before any work starts, and have the repair backed by our 365-Day Done Right Promise in writing for one full year.
Written by Travis Oakley, Owner at Brennan Roofing Co San Francisco, serving San Francisco and the surrounding Bay Area.