Owens Corning
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Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Why San Francisco Homeowners Choose Owens Corning Roofing
Brennan Roofing Co San Francisco provides independent Owens Corning roofing repair, replacement, and maintenance across every San Francisco neighborhood, from the Outer Sunset to Bernal Heights. We are not an Owens Corning authorized dealer or factory branch, and we have never claimed to be. What we are is an independent contractor whose crews have torn off, installed, and repaired hundreds of Owens Corning Duration and Oakridge systems in this city’s fog, wind, and salt air. When you call (831) 318-8819, you get a live person, a written price before any work starts, and a full-year guarantee in writing.
That last part matters in San Francisco. This is not a forgiving climate for roofing. Fog keeps north-facing slopes damp for six months a year. Wind off the Pacific drives rain sideways into ridge caps and flashing. Salt air eats at exposed fasteners. And half the housing stock is wood-framed Victorians and Edwardians built between 1880 and 1920, with steep pitches, ornate eaves, and roof penetrations that were never detailed for modern shingle systems. Owens Corning products hold up well here when they are installed correctly and maintained honestly. Most of what we fix is not shingle failure. It is installation failure, flashing failure, or neglect in places homeowners cannot see from the ground.
Our Owens Corning work starts with a diagnosis you can understand. We do not sell roofs. We read them.
Why Trust Brennan Roofing Co San Francisco for Your Owens Corning Roofing?
Travis Oakley, the owner of Brennan Roofing Co San Francisco, grew up in the San Gabriel Valley and learned the trade through the construction technology program at East Los Angeles College before moving his operation north. He and his crews have been working San Francisco roofs for years, from flat torch-down on Sunset District flats to steep Victorian shake replacements near Alamo Square, with similar expertise available for those needing Owens Corning in Berkeley. Travis is known for reading a roof honestly: he will tell you what needs replacing now, what can wait two seasons, and what a salesman might oversell you on. When he is not on a job or doing estimates, he keeps a small vegetable garden in his backyard, tomatoes mostly, with mixed results depending on the fog.
Our technicians work on Owens Corning systems every month, not occasionally. They know how Duration shingles lay on a 6:12 pitch versus a 3:12 pitch. They know which OC VentSure ridge vent profiles match which shingle profiles, and what happens when someone substitutes a cheaper 3-tab ridge cap on a Duration field. That specific knowledge is what keeps a repair from turning into a second leak six months later.
Every Owens Corning job we take in San Francisco follows the same Garrison Standard: a written price before any work begins, a background-checked uniformed technician who shows up inside the promised window, and a workmanship guarantee in writing for one full year. If our repair fails inside that year, we come back and fix it at no charge. That is not a slogan. It is in the paperwork.
Styles & brands we work with






Common Owens Corning Roofing Problems We Fix in San Francisco
- Blistering and granule loss on older Duration Series shingles. We see this most often on south-facing slopes in the Outer Sunset and Excelsior, where direct afternoon sun hits the shingle surface after a morning of heavy fog. The rapid thermal swing causes the asphalt to expand and contract, and over 15 to 20 years the granule layer starts to slough off. Blistering without granule loss is often cosmetic. Blistering with heavy granule loss means the shingle is losing its UV protection and needs replacement.
- Wind uplift and shingle tab cracking along ridgelines. In the Richmond District, sustained afternoon wind gusts off the Pacific hammer two-story flat and low-slope roof combinations. Shingle tabs at the ridge take the brunt of it. If the original installer used short nails or nailed too high on the shingle, the tabs lift, crack, and eventually tear off. We find this on Owens Corning roofs that are only 8 to 10 years old. A proper repair means re-nailing with correct placement and replacing the damaged tabs with matching Duration or Oakridge shingles.
- Mold and algae streaking on north-facing slopes. In fog-bound areas like Twin Peaks and Diamond Heights, the north sides of Owens Corning roofs get almost no direct sun from October through May. Algae and moss establish themselves in the granule layer. The streaks are not structural failure, but left alone, moss roots can lift shingle edges and hold water against the decking. We clean and treat these roofs and flag any sections where the organic growth has already compromised the shingle seal.
- Underlayment deterioration around penetrations on older installations. Owens Corning roofs installed 20 or more years ago often used felt paper underlayment rather than the modern synthetic Deck Defense material. Around chimneys and skylights, that felt paper breaks down faster than the shingles above it. The shingles look fine from the ground. The underlayment is gone. By the time water shows up on the ceiling, the decking underneath has usually been wet for months.
- Flashing separation at roof-to-wall transitions. San Francisco’s Victorians and Edwardians have dozens of roof-to-wall intersections, dormer cheeks, and sidewall terminations. Step flashing on Owens Corning installations from the 1990s and early 2000s was often aluminum, which corrodes faster in salt air than copper or painted galvanized. We frequently replace corroded step flashing and re-integrate it with the existing Owens Corning shingle courses.
Owens Corning Parts & Our Repair-vs-Replace Approach
We use genuine Owens Corning components whenever we tie into an existing Owens Corning roof. That means matching Duration or Oakridge shingle colors, OC VentSure ridge vents, and Deck Defense synthetic underlayment when a section gets opened up. For repairs on older systems where an exact color match is impossible because the dye lot has shifted with age, we layer compatible architectural shingles that preserve the integrity and warranty of the surrounding roof. We tell you when the color will not be a perfect match. Some contractors will not. We would rather you know before the shingles go on.
The repair-versus-replace call is straightforward. If a leak is isolated to a flashing point or a small section of field shingles, we patch it correctly and document what we did. If the surrounding shingles are brittle, losing granules, or lifting at the edges, we tell you that patching is a short-term play and that a targeted section replacement is cheaper than chasing the same leak every winter. No pressure. Just math. Call (831) 318-8819 for a written quote on either path.
Our Owens Corning Service Process – Step by Step
- 1
Diagnosis. We walk the roof, check the flashing, the ridge caps, the vent boots, and the shingle condition. We look for the specific Owens Corning failure patterns common in San Francisco: wind-lifted tabs on exposed elevations, granule loss on south slopes, and underlayment breakdown around penetrations. You get a written diagnosis and a written price before any work starts.
- 2
Repair or installation. We use correct Owens Corning components: matching Duration or Oakridge field shingles, proper OC VentSure ridge caps instead of cheap 3-tab substitutes, and synthetic Deck Defense underlayment where sections are opened. Every penetration gets re-booted or re-flashed, not just the one that is leaking.
- 3
Testing. We water-test repairs where possible, usually with a controlled hose spray at the repaired seam or flashing point. On larger installations we check nail placement, shingle alignment, and ridge vent airflow before we pack up.
- 4
Documentation and guarantee. You get a written summary of what we did, what we found, and what we recommend watching. The workmanship is guaranteed in writing for one full year. If it fails inside that year, we come back at no charge.
See the difference
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AfterOwens Corning Products We Service & Install in San Francisco
We work on the full Owens Corning residential lineup: Duration Series shingles, Oakridge shingles, TruDefinition Duration Designer Colors, and Berkshire shingles. We stock common Duration and Oakridge colors locally for fast turnaround on repairs, including Driftwood, Onyx Black, and Brownwood. We keep OC VentSure ridge vents and Deck Defense synthetic underlayment on hand for tie-ins and section replacements. For less common Berkshire colors we special-order from local supply houses, usually arriving within a few days. If you have an Owens Corning roof of any age or series, we can tell you what you have and what it needs.
We Also Service These Brands
Owens Corning is one strong line, but it is not the only one we work with. We also install and service GAF and CertainTeed systems, along with IKO, Atlas, Tamko, and Boral. The same crews, the same written-price standard, and the same full-year guarantee apply no matter which shingle is on your roof.
FAQs – Owens Corning Roofing Service in San Francisco
No. We are an independent Owens Corning service provider. We are not an authorized dealer, factory branch, or warranty administrator for Owens Corning. That independence does not limit our technical ability; it means we are not obligated to sell you a new Owens Corning roof when a repair is the honest answer. Our workmanship carries our own one-year written guarantee regardless of manufacturer status.
Usually, yes, with one caveat. We stock the most common Duration colors locally and can match most installations from the last 10 to 12 years closely. On older roofs, the original dye lot has faded or shifted, and a fresh bundle of the same named color will not be invisible against the existing field. We will show you the difference before we install, and we can often feather the transition so it is not noticeable from the street. Call (831) 318-8819 and we will match your shingle in person.
Because one side of your roof gets more solar punishment than the other. In San Francisco, south-facing slopes get direct afternoon sun after a morning of fog and cool temperatures. That thermal cycling stresses the asphalt in the shingle and can cause blistering over time. If the blisters have not popped and the granules are still attached, the roof is generally sound. If the blisters are open and the shingle felt is exposed, that section is losing waterproofing and should be replaced. We will tell you which condition you have.
Only as a temporary fix, and even then, not often. Metal valleys can be installed over existing shingles in a valley to stop an active leak, but the underlying shingles and underlayment are already compromised if water got through. The correct repair is to cut back the valley on both sides, replace the damaged underlayment with synthetic Deck Defense, and relay the valley with shingles or matching metal. A metal patch over failing valley shingles buys you a season at best and hides the real problem.
Usually not. Black streaks on Owens Corning shingles are almost always algae, not shingle failure. The algae feeds on the limestone in the asphalt and thrives on the damp, shaded north slopes of San Francisco roofs in fog-bound areas like Twin Peaks and Diamond Heights. The fix is a careful cleaning with a roof-safe solution, not a new roof. We will inspect while we are up there and confirm the shingles are still sealing properly.
No. Torn or deteriorated underlayment around a specific penetration, chimney, or valley can usually be repaired by removing the shingles in that section, replacing the underlayment with synthetic Deck Defense, and re-installing the shingles. You only need a full roof replacement when the underlayment failure is widespread across multiple roof planes. We will show you photos of what we find so you can see the scope for yourself before deciding.
Owens Corning roof repair in San Francisco typically runs $400 to $1,800 depending on the scope. A single vent boot replacement is on the low end. A chimney re-flashing with new step flashing and counter-flashing runs higher. A full Owens Corning Duration roof replacement on a typical San Francisco Victorian or Edwardian runs $14,000 to $35,000 depending on square footage, pitch, tear-off requirements, and decking condition. Every job gets a written line-item price before any work begins. Call (831) 318-8819 for an exact quote on your roof; estimates are free.
Book Your Owens Corning Service in San Francisco, CA
If your Owens Corning roof is leaking, lifting, or simply due for an honest assessment, call (831) 318-8819. A live person answers. We will schedule a written estimate, show up when we say we will, and tell you the truth about what your roof needs and what it does not. Travis Oakley and the Brennan Roofing Co San Francisco crew have been reading San Francisco roofs long enough to know the difference.
Written by Travis Oakley, Owner of Brennan Roofing Co San Francisco, serving San Francisco roofs with the Garrison Standard since 2000.