Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
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AfterFast, Reliable Roof Repair Across San Francisco
Roof repair in San Francisco usually costs between $350 and $1,800 depending on what failed, and most jobs are done in a single visit. The city’s fog-driven climate and dense rowhouse stock mean the failure you’re seeing is rarely a simple shingle issue – it’s usually membrane saturation, parapet flashing, or a clogged interior drain. We’ve worked on Victorians in the Mission, Edwardians in the Inner Richmond, and stucco homes throughout the Sunset. If water is coming in, call (743) 200-8347 and we’ll send a technician whose name and photo you’ll have before they knock.
Why Mercer Roofing Is San Francisco’s Preferred Roof Repair Company
Most roofers in San Francisco will quote you over the phone and send a crew you’ve never met. We don’t work that way. Every Mercer Roofing technician is background-checked, identity-verified, and badged under the Threshold Standard – and before they arrive, you get their name and photo. That matters in a city where attached rowhouses mean whoever comes to your door may need to walk through your living room to reach the roof hatch. Founded in 2000 and part of the Threshold Group family of home-service companies, Mercer Roofing sends uniformed, photo-badged professionals on every visit, with a written price in hand before any work starts.
San Francisco homeowners tell us the same thing: they want to know who is coming, and they want the price locked before the first nail goes in. We do both. The 365-Day Done Right Promise covers every repair we make – if it’s not right within a year, we make it right, with a free second visit included. No fine print, no re-quoting. That’s the standard we hold in every San Francisco neighborhood from the Outer Sunset to Potrero Hill.
Shingle Roof Repair in San Francisco
Shingle Roof Repair in San Francisco is less common than people expect – most of the city’s housing stock carries flat or low-slope membranes – but the pitched roofs on Edwardian bay windows, dormers, and some freestanding homes in the Richmond and Sunset still fail in predictable ways. Cracked or blown-off asphalt shingles, failed nail heads, and damaged ridge caps let fog-driven moisture work under the shingle course, and because the marine layer can keep surfaces wet for weeks, the rot advances faster than it would in a drier market. San Francisco’s building code also requires specific nailing patterns for high-wind exposure zones along the coastal edge, and we follow them on every repair.
Typical shingle repair in San Francisco runs $350 to $850 for localized replacement, and $1,100 to $2,400 when the underlayment or decking beneath has already started to rot. We use manufacturer-recognized brands including GAF and CertainTeed, and we match existing shingle color as closely as the original run allows. If you’re not sure whether it’s a shingle problem or a flashing problem, call us – the estimate visit costs nothing.
Damaged Flashing and Leaks at the Roof Edge
On San Francisco rowhouses, the most common shingle-adjacent failure is at the headwall and step flashing where a pitched section meets a parapet or party wall. Fog-driven water follows the flashing seam, not gravity, and capillary action draws it into the wall cavity long before you see a ceiling stain. In the Richmond and Sunset, where homes sit in the fog for months at a time, we replace flashing with a full bead of sealant and a proper counter-flashing overlap rather than relying on caulk alone.
Matching Older Roof Colors and Profiles
Homes built in the 1920s through 1940s across the Sunset and Richmond often carry shingle colors and profiles that aren’t manufactured anymore. We stock local color-matched bundles for the most common San Francisco shingle types and can source discontinued profiles through our GAF and CertainTeed supply relationships – faster than most contractors, because we keep those relationships active, not just on paper.
Storm Damage Roof Repair in San Francisco
Storm Damage Roof Repair in San Francisco is rarely about what other cities call a storm. The city gets about 20 inches of rain a year, but the winter atmospheric rivers that do hit can tear loose membrane edges, lift flashing, and overwhelm flat-roof drains in a matter of hours. More often, the “storm” is a wind event that rips a section of modified bitumen away from its termination bar or sends a branch through a skylight on a flat roof. When that happens, homeowners need a tarp or temporary patch immediately, and a permanent repair scheduled as soon as the weather clears.
Emergency storm repair in San Francisco typically runs $500 to $1,200 for temporary mitigation on a flat roof, and $1,400 to $4,000 if a permanent membrane section or flashing repair is needed right away. The cost depends on roof access – if you’re in a zero-lot-line rowhouse in the Castro or Mission, we may need to hoist materials over the front parapet, which adds labor but gets done correctly the first time. Call (743) 200-8347 and a live person answers, day or night.
Mid-Repair Protection for the Next Storm Front
When a storm system is still moving through, the right repair often means stopping the water now and scheduling the permanent fix once the roof is dry. We carry UV-stable tarping and can secure temporary protection across a flat or low-slope membrane without penetrating the roof surface. Temporary mitigation is a real skill – done poorly, it leaks again within days. Done right, it holds until we can strip and re-lay the affected membrane field.
Post-Storm Inspection for Hidden Membrane Lifts
After a wind event, the damage you can see is rarely the whole story. Wind can lift the membrane away from the drain flashing and create a flap that doesn’t leak until the next fog cycle saturates it. In San Francisco, that fog can last for weeks, so we inspect the entire field, not just the visible rip. If you see a ceiling stain after a storm, the membrane lift may be on the opposite side of the roof from the stain – water travels along the deck before it finds a path down.
Trusted Brands We Service in San Francisco
We install and repair shingle and membrane systems from GAF, CertainTeed, and Owens Corning, with Atlas, Tamko, and Boral available for specific color and profile matches. That matters in San Francisco, where historic and overlay districts often require a specific surface texture or color, and where a mismatched shingle patch on a Victorian can trigger a review letter from the Planning Department. Because we stock local parts for the city’s most common roofing systems – including GAF EverGuard TPO and standard modified bitumen in both smooth and granulated finishes – turnaround on San Francisco repairs is faster than it would be if we had to order every roll from a warehouse in the East Bay. If your roofer has to wait three days for a membrane roll, the fog has three more days to ruin your ceiling.
Common Roof Repair Problems We See in San Francisco Homes
- Fog-driven membrane saturation in the Outer Sunset and Inner Richmond: The official rainfall is only about 20 inches a year, but the marine layer saturates flat roofs for weeks or months at a stretch. That persistent moisture causes micro-cracking in BUR and modified bitumen systems – and algae growth that holds even more water against the membrane. We see this failure pattern constantly in the fog belt, and it’s essentially absent in Oakland or San Jose.
- Zero-lot-line rowhouse access in the Castro and Mission: Many of these homes have no side yard at all, which means every roll of membrane, every bundle of shingles, every bucket of sealant has to go over the front parapet by rope and pulley or through the client’s living room. A bid that doesn’t account for that access is a bid that will change on you mid-job. Ours doesn’t.
- Parapet and party-wall flashing failures on Victorians and Edwardians: The junction where a flat roof meets a shared wall is the single most common leak point in San Francisco’s attached rowhouse stock. Flashing there fails from the constant fog-wetting and drying cycle, and because the wall is shared, getting it wrong means damaging a neighbor’s interior too. We treat party-wall flashing as a precision detail, not an afterthought.
- Clogged interior drains and scuppers on flat roofs: In a city of flat roofs, the drain is the weak point. Leaves from street trees, accumulated debris, and decades of deferred maintenance clog interior drains, and water backs up across the entire roof field. A $150 drain cleaning often prevents a $2,500 membrane replacement – and we check drains on every visit to a San Francisco flat roof, even if the call was for something else.
Pricing for Roof Repair in San Francisco, CA
Here’s what we charge in San Francisco, and we don’t play pricing games. A simple shingle replacement on a pitched section runs $350 to $850. Flat roof membrane patches on BUR or modified bitumen run $700 to $1,800 depending on the size of the field and whether we need to address underlying decking. Flashing repair at a parapet, party wall, or chimney runs $400 to $1,200. A full membrane re-cover on a typical Inner Richmond or Sunset flat roof is a different conversation – that’s replacement territory, and you can read more on our Roof Repair page. Every job starts with a written estimate, and that price is the price. No change orders, no add-ons, no surprises on the invoice. The 365-Day Done Right Promise backs every repair in writing. Call (743) 200-8347 to schedule your free estimate.
We Also Serve Cities Near San Francisco
Beyond San Francisco, our crews handle repairs in Daly City, Brisbane, Sausalito, and South San Francisco. If you’re just over the county line and need flat roof work or shingle repair, our San Francisco dispatch coordinates scheduling throughout the Bay Area. Same written-price-before-work standard, same badge-at-the-door policy, same 365-day guarantee.
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
Because the city’s housing stock is dominated by flat or low-slope membrane roofs on zero-lot-line rowhouses, and that drives three cost factors: material hoisting over parapets or through interiors instead of staging in a yard, party-wall flashing work that requires precision around shared walls, and the fog-driven failure mode that means a small visible leak often hides a larger saturated membrane field. Oakland and San Jose have far more pitched shingle roofs with side-yard access, which is faster and cheaper to work on. Our written quote accounts for all of it up front, so you’re not surprised at the end. Call (743) 200-8347 for a free estimate.
That’s fog-driven membrane saturation, and it’s the signature failure mode of the Inner Richmond and Outer Sunset. The marine layer sits on these neighborhoods for weeks or months, and the constant moisture plus UV cycling at the fog edge causes hairline micro-cracking in modified bitumen and BUR systems. Water works its way through those cracks slowly, saturates the underlying insulation, and eventually finds a path to your ceiling – often far from the actual entry point. The fix is to replace the saturated membrane field and re-flash the parapet and drain penetrations, not to keep patching individual cracks. Call (743) 200-8347 and we’ll send a technician who can read the whole roof, not just the wet spot.
In most San Francisco rowhouses, no – and anybody who tells you otherwise without seeing the property is guessing. If you’re in a zero-lot-line building in the Castro or Mission with no side-yard access, materials have to go over the front parapet by rope and pulley, and the crew still typically needs to reach the roof hatch through the interior for at least part of the job. We plan for that in the bid and we keep the interior path covered and clean. If you do have a side passage or a rear deck with lift access, we’ll use it. The point is we tell you before we start, not after. Your technician’s name and photo come to you before arrival, and they badge in with photo ID at the door.
Most repairs don’t require a permit. San Francisco’s building code allows routine repair of existing roofing covering up to a certain square footage without one, as long as you’re not altering the structural deck or changing the roof’s profile. However, if your home sits in a historic district or is subject to overlay review – which is true for much of the Western Addition, large parts of the Mission, and many Victorians – you may need Planning approval before changing the visual character of the roof. We handle those conversations every week and will tell you on the estimate visit whether your repair triggers review. If it does, we’ll file the paperwork and pull whatever permit is required before any work starts.
Look at three things: what exactly is included, what access method they priced, and what guarantee they put in writing. A low bid that assumes side-yard staging on a Castro rowhouse is not a real bid – it’s a teaser that will get revised when the crew shows up and has to hoist everything over the parapet. Ask each bidder to itemize the membrane brand, the square footage of replacement, the flashing detail at party walls and parapets, and whether drain work is included. Then ask about the guarantee: ours is 365 days, in writing, on every repair, with a free second visit if it fails. That’s the whole point of comparing. Call (743) 200-8347 for a written quote you can hold up against any other.
Written by Grant Whitlock, Owner at Mercer Roofing, serving San Francisco since our founding in 2000.