Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Before
After
Before
After
Before
AfterGAF Roofing in San Francisco, CA | Tilehurst Roofing
We’re our Roofing Company in San Francisco, providing GAF roof repair, replacement, and leak diagnostics across the city. The single biggest difference in our GAF work here: we diagnose for fog condensation and salt air, not rainfall, because San Francisco roofs fail from moisture on 100+ foggy days a year, not from storms. Our crews have installed and repaired GAF systems in this city for over a decade, and we know exactly where these roofs fail and why. Call (945) 303-9821 for a free estimate with a written price before any work starts.
Why San Francisco Residents Choose Us for GAF Service
GAF makes solid roofing products, but their performance depends entirely on how they’re installed and maintained in a specific climate. We’re an independent GAF service provider offering our Roof Repair in San Francisco, which means we don’t answer to a manufacturer’s sales targets. We answer to homeowners in the Outer Sunset, Noe Valley, and the Richmond who need a roof that stays dry through a fog season that never really ends.
Our owner, Greg Holloway, learned roofing at Los Angeles Trade-Technical College under instructors who were working roofers. They treated a sloppy flashing job like a surgeon treats a bad stitch. He’s carried that standard through two decades of roofing work, and it’s why our crews show up in the window we promise and quote the full number before a single shingle comes off. Know the price before the first tile moves.
We use genuine GAF membranes, shingles, and accessories whenever they’re available for the system in place. When a quality aftermarket flashing or fastener outperforms the OEM part in salt-air conditions, we specify that instead and tell you why. Every repair carries a written guarantee. If it fails inside the guarantee period, we return at no charge. That’s the GAF sales & service standard we hold ourselves to, backed by our 365-Day Done Right Promise.
Common GAF Roofing Problems We Solve in San Francisco
- Fog-condensation wicking at Liberty SBS seam laps. GAF Liberty SBS self-adhered modified bitumen is common on San Francisco flat roofs, especially in the Outer Sunset and Outer Richmond. The problem here isn’t rain. It’s the near-daily marine layer saturating seam edges, wicking into the self-adhered lap, and delaminating the membrane over time. We see this failure pattern on the west side more than anywhere else in the city.
- Salt-air corrosion of GAF metal flashings and fasteners. Pacific and Bay salt air eats GAF metal edge flashings, drip edge, and fastener heads faster here than in San Jose or Walnut Creek. On Victorian and Edwardian rowhouses with original wood framing, corroded fasteners loosen attachments and let moisture into the deck. We replace them with marine-grade options and reinforce the surrounding seal.
- Ponding water on EverGuard TPO when drains or scuppers are slightly compromised. GAF EverGuard TPO single-ply holds up well, but San Francisco flat roofs live or die by drainage. Even a partially blocked scupper means ponding water that causes seam separation and membrane blistering, independent of any rainfall. We clear, repair, or re-set drains as part of every TPO service call.
- Layered Ruberoid torch-down failures on 1900s wood-frame construction. Many San Francisco rowhouses still carry original built-up tar-and-gravel roofs that have been layered with GAF Ruberoid torch-down multiple times. Trapped moisture between plies hides deck rot on the original wood framing beneath. We find it during leak diagnostics, not after another layer gets slapped on top.
- Parapet flashing failures at shared party walls. On attached rowhouses in the Mission, Castro, and Noe Valley, parapet walls are shared between properties. You can’t properly re-flash the base of a parapet without coordinating with the neighbor. We’ve done this enough times to know how to handle the conversation and the flashing correctly.
GAF Service in San Francisco: What Local Conditions Mean for Your Equipment
San Francisco’s fog delivers moisture on more than 100 days a year without a single drop of rain. This is the insight that changes how GAF roofs must be diagnosed here. GAF membrane seams and parapet flashings in San Francisco fail from condensation wicking, not storm-driven water. The marine layer sits on flat roofs in the Outer Sunset for months at a time, and that moisture works into every seam, lap, and flashing edge at a pace that rainfall never matches. It means leak diagnostics here must be scheduled during foggy mornings, not after rain, to catch the actual intrusion path. A roofer who only shows up after a storm will miss the problem entirely, because the water that’s causing the damage isn’t from the storm. It’s from the fog that started at 6 a.m. and burned off by noon. We schedule our San Francisco leak assessments accordingly, including up on 19th Avenue and the avenues west of it where fog dwells longest.
This also explains why the repair-versus-replace math works differently in San Francisco than in most cities. If a GAF roof has more than 30-40% compromised membrane area or wet decking, we recommend full replacement rather than repeated patches. Layered repairs in the fog belt almost always fail within a few seasons. We’ve pulled apart roofs in the Sunset where three generations of patches sat on top of each other, all leaking at the same seams. One proper replacement costs less over five years than three patch jobs that fail.
GAF Models & Products We Service in San Francisco
We work on the full range of GAF systems found on San Francisco roofs. On the pitched sections of Victorian and Edwardian homes, that’s GAF Timberline HDZ architectural shingles. On the flat and low-slope sections that dominate the city’s housing stock, we service GAF Liberty SBS self-adhered modified bitumen, GAF EverGuard TPO single-ply membranes, and GAF Ruberoid torch-down systems, including older built-up roofs that have been layered over multiple times.
We stock the most common GAF accessories locally for fast San Francisco turnaround, which matters when a leak is active. When an OEM part isn’t on hand, we’ll tell you what aftermarket option we’re specifying and why it holds up better in salt-air conditions. No mystery substitutions, ever. The written quote lists exactly what goes on your roof.
We’re proud to serve homeowners throughout the San Francisco service area, and we carry that same standard into every neighborhood from the Outer Richmond to the Bayview.
GAF Service Pricing in San Francisco
Most GAF roof repairs in San Francisco run $450-$1,400 for leak repair and flashing work, depending on what we find once we open the roof. Replacing a membrane section on a flat roof typically falls between $1,800 and $4,200, again depending on the system and the deck condition beneath it. Full GAF roof replacements on San Francisco rowhouses run anywhere from $14,000 to $38,000. The wide spread comes from the decking, the access, and whether shared parapet walls require neighbor coordination.
Every estimate we write includes a line-item breakdown so you see exactly where the money goes. The price you get is the price you pay, before any work starts, and it never changes mid-job. Call (945) 303-9821 to schedule a free estimate, and we’ll put the numbers in writing while we’re still on the roof.
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 - GAF Roofing in San Francisco
Yes, in most cases a Liberty SBS membrane can be repaired at the seam laps or flashing points without replacing the entire system, as long as the decking beneath is dry and the membrane has less than 30-40% compromised area. If fog condensation has delaminated seams across a wide section, we’ll recommend replacement rather than patching, because layered repairs in San Francisco’s fog belt rarely last more than a few seasons. Call (945) 303-9821 and we’ll assess what you actually need before recommending anything.
San Francisco roofs sit in fog on 100+ days a year, so GAF membrane seams and flashings fail from condensation wicking, while San Jose and Walnut Creek roofs mostly fail from sun, heat, and seasonal rain. The salt air off the Pacific and the Bay also corrodes metal flashings and fasteners here far faster than inland. It changes what we look for during diagnostics and which materials we specify for repairs.
Yes, the San Francisco Department of Building Inspection requires a permit for full roof replacements. Skipping it is common, but it leaves the next buyer with an unpermitted roof that surfaces during escrow inspections in one of the nation’s most litigious real-estate markets. We pull permits and pass inspections on every replacement we do in San Francisco.
For most flat or low-slope roofs on Victorian and Edwardian rowhouses, we recommend GAF Liberty SBS self-adhered modified bitumen. It handles the fog, the salt air, and the movement of wood-framed structures better than most alternatives. For a single-ply application, GAF EverGuard TPO works well when drainage is properly maintained. Call (945) 303-9821 and we’ll walk the roof with you to pick the right system.
Fog affects shingles differently than membranes. Timberline HDZ shingles handle the moisture itself fine, but the chronic dampness promotes moss and algae growth on the north-facing pitches of San Francisco homes, which traps moisture against the shingle surface and shortens its life. The salt air also accelerates corrosion of the fasteners beneath. Regular maintenance and proper flashing are what keep the pitched sections healthy. Call (945) 303-9821 to schedule an inspection.
Service Areas Near San Francisco
Beyond San Francisco itself, our crews serve homeowners in nearby Bay Area markets, including Oakland, Daly City, South San Francisco, and Pacifica. We also maintain service teams for GAF service in Fresno and GAF service in Sacramento, so if you have a property outside the city, we can still handle the roof.
Book Your GAF Service in San Francisco Today
If your GAF roof is leaking, blistering, or just nearing the end of its life, call (945) 303-9821. We’ll schedule a free estimate, show up in the window we give you, and hand you a written price before any work starts. A live person answers 24 hours a day.
Written by Greg Holloway, Owner at Tilehurst Roofing, serving San Francisco with independent GAF roofing service since 2000.