Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Before
After
Before
After
Before
AfterFast, Reliable Roof Replacement Across San Francisco
If your San Francisco flat roof is failing, you already know the signs: water stains spreading across the ceiling, blistering membrane, moss colonizing the low spots. A full Roof Replacement on a typical San Francisco rowhouse runs between $14,000 and $32,000 depending on square footage, decking condition, and membrane spec. You’ll see your exact number in writing before any work starts. Call (424) 766-4937 to schedule a free estimate with a roofer who actually understands fog-belt roofs.
We know San Francisco the way a neighborhood roofer should: we’ve torn off tar-and-gravel systems in the Mission with three generations of patches, replaced torch-down membranes in the Outer Sunset that never dried between fog events, and rebuilt rooftop-deck curbs in Noe Valley that were leaking through unpermitted lag bolts. The roofs here aren’t like roofs in Oakland or San Jose, and they don’t fail the same way either. Erik Lindgren and the Birchbark crew work on San Francisco roofs every week, and we bring the right materials and the right fasteners for this climate. Not the inland-spec version that rusts out in three years.
Why Birchbark Roofing Is San Francisco’s Preferred Roof Replacement Company
Homeowners in San Francisco call us because we show up with a written price and a crew that treats the house like a home. That means shoe covers at the door, drop cloths through the hallway, and a photo of the completed clean-up before we leave. If you have kids or a dog, we coordinate the door schedule with you so nobody gets out and nothing gets tracked in. Pet-safe products where there’s a choice, every time.
Every Birchbark job is backed by the 365-Day Done Right Promise: if the work isn’t right, we make it right. That guarantee is stamped on every replacement we do in San Francisco, from a small flat-roof patch in the Castro to a full tear-off in the Outer Richmond. A live person answers our phone 24/7, so when you call about a leak in the Western Addition on a Saturday morning, you’re talking to a person, not a voicemail tree.
We’re part of the Cedarwell family of roofing companies, and we hold every San Francisco job to the Cedarwell Care Promise. The C.A.R.E. values aren’t marketing copy to us: Clean up like it is our own home. Ask before we move or touch anything. Respect the family’s time and quiet hours. Explain the price before the work. Those four things govern how we run a crew on a roof in San Francisco.
Flat Roof Replacement in San Francisco
Flat Roof Replacement in San Francisco is the core of what we do, because most of the city’s housing stock was never built for pitched shingle roofs. The Victorians and Edwardians in the Mission, Castro, and Noe Valley, the stucco tract homes in the Outer Sunset and Outer Richmond, they all run flat or near-zero-pitch. That changes everything about materials and methods. A flat roof on a San Francisco rowhouse typically runs $16,000 to $28,000 for a full tear-off and new membrane, and you can expect the job to take three to five days depending on decking repairs.
Marine-Layer Membrane Selection
The fog belt isn’t just a nuisance; it’s a corrosion engine. In the Outer Sunset and Outer Richmond, standard galvanized fasteners and asphalt-based flashing sealants fail within three to four years. We spec stainless or hot-dip hardware and marine-grade finishes as a matter of course on any San Francisco job west of Twin Peaks. The coastal-spec version costs more up front, typically 10 to 15 percent over the inland spec, but the cheap spec fails within a decade and sends you right back into another tear-off.
Torch-Down and TPO Detail Work
Torch-down modified bitumen has been the default San Francisco flat-roof system for decades, but it needs heat, and San Francisco’s marine layer is the enemy of heat. Seams that don’t fully cure between fog events blister and delaminate. For most clients, we recommend GAF EverGuard TPO mechanically fastened over a properly sloped deck: it welds at lower temperatures, resists moss, and holds up to constant damp better than asphalt-based systems. Your specific roof may need something different; you’ll see the spec in writing before we start.
Roof Installation in San Francisco
Roof Installation in San Francisco on new construction or major additions gives you a blank slate, which is rare in a city where most roofs have a hundred years of history on them. New-construction roof installation in San Francisco runs $18,000 to $35,000 depending on the system, and often includes tapered insulation to build slope into a flat deck. We work with GAF, CertainTeed, and Owens Corning systems, and we’ll walk you through which membrane fits your building’s orientation to the fog.
New Construction and Deck-Ready Roofs
If you’re building new or adding a roofline, we coordinate with your general contractor so the roof assembly is built for San Francisco from day one. That means proper slope, cricket details, and blocking installed in the framing stage, not retrofit after a leak. Ask us during framing, not after the drywall goes up.
Rooftop Deck Curbs and Penetration Repair
Rooftop decks are a signature San Francisco upgrade, and they’re also a signature source of leaks. When decks are lag-bolted directly through the membrane into the structural deck, the DBI now flags those penetrations during permit review and forces remediation. We build the curb, we flash it properly, and we use stainless hardware that won’t rust in the fog. If the deck is going on after the roof, we’ll make sure the two systems don’t fight each other.
Trusted Brands We Service in San Francisco
We install and service roofs from GAF, CertainTeed, Owens Corning, and IKO, and we carry the materials that actually hold up in San Francisco’s fog belt. That matters when a seam fails mid-season: we’re not waiting on a parts order from the Central Valley. For flat-roof work we lean on GAF EverGuard TPO and CertainTeed Flintlastic systems, depending on budget and exposure. For any pitched sections, we run Owens Corning Duration or GAF Timberline architectural shingles. All are backed by manufacturer warranties, and we’ll register your system with the manufacturer so the warranty is actually enforceable.
Common Roof Replacement Problems We See in San Francisco Homes
- Fog-belt fastener corrosion: Galvanized nails, drip edge, and flashing rust and stain within three to four years in the Outer Sunset and Outer Richmond, letting water wick through the fascia and underlayment before the membrane itself shows any failure. We replace with hot-dip galvanized or stainless hardware on every fog-belt roof.
- Rooftop deck penetrations: Unpermitted decks lag-bolted through flat Victorian membranes create a dozen chronic seam leaks. The DBI flags them at permit pull now, so contractors have to cut out the breach, sister damaged joists, and rebuild the curb. We do that work as part of the roof scope.
- Marine-layer seam blistering: Torch-down seams that don’t fully cure between fog events blister along valleys and low spots, and moss colonies undermine flashing and ridge vent seals. TPO and proper slope solve most of these failures.
- Layered patch jobs: We tear off roofs in the Mission and Castro that have five or six re-roofing layers on them, each one trapping moisture against the deck. The weight alone strains old framing, and the trapped moisture rots sheathing from the inside.
Pricing for Roof Replacement in San Francisco, CA
A flat roof replacement on a typical San Francisco rowhouse runs $14,000 to $32,000. A small single-story flat roof in the Sunset might land at the low end; a large Victorian with decking repairs and structural sistering in Noe Valley can push toward the high end. The coastal-spec hardware and marine-grade flashing add roughly 10 to 15 percent over an inland-spec bid, but they buy you a roof that lasts 20 years instead of failing in 10. New-construction roof installation runs $18,000 to $35,000. Call (424) 766-4937 and we’ll give you a written line-item price before any work starts, so you can compare bids apples to apples.
We Also Serve Cities Near San Francisco
Birchbark Roofing serves Roof Replacement in San Francisco and the surrounding communities, including Daly City, Brisbane, Sausalito, and South San Francisco. The fog doesn’t stop at the city line, and neither do we. If you’re on the Peninsula or across the bridge and dealing with a flat-roof leak, call us at (424) 766-4937 and we’ll schedule a free estimate.
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 Replacement in San Francisco
In most cases we see, the answer is fog-belt corrosion and improper penetration details. If the previous contractor used standard galvanized fasteners and asphalt flashing on a roof in the Outer Sunset or Outer Richmond, those materials are already failing within three to four years. If there’s a rooftop deck, the penetrations are likely the source. Call (424) 766-4937 and we’ll diagnose the actual failure mode, not just patch the symptom.
Yes. The SF Department of Building Inspection requires a permit for any flat roof replacement that involves structural decking work, and if a rooftop deck is present, the DBI will review the penetrations as part of the permit. If the deck was lag-bolted through the membrane, you’ll have to remediate those breaches. We pull the permits, handle the inspections, and make sure the final roof passes.
The best performers we’ve installed in San Francisco’s fog belt are GAF EverGuard TPO welded over a properly sloped deck, paired with hot-dip galvanized or stainless fasteners and marine-grade flashing. CertainTeed Flintlastic torch-down works on tighter budgets but needs full cure time. The material is only half the story; the fasteners and seam details determine whether the roof lasts five years or twenty.
Look at the fastener spec, the flashing metal, and the slope detail. One bid may price galvanized hardware and standard drip edge; the other may price stainless and marine-grade. That’s the difference between a roof that rusts out in three years and one that holds for two decades. Ask both contractors to put the hardware and flashing spec in writing. We’ll show you ours line by line.
Occasionally, if the framing allows it. Most San Francisco Victorians and Edwardians were built with flat or very low-slope decks, and adding pitched architectural shingles means reframing the roof plane, rebuilding the parapet, and often a structural review. It’s a bigger job than a membrane replacement, typically $35,000 to $60,000. For most rowhouses, a properly sloped membrane roof is more practical. We’ll look at your framing and give you an honest recommendation.
Written by Erik Lindgren, Owner at Birchbark Roofing, serving San Francisco with flat-roof replacement and installation expertise.