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 Jose
Roof repair in San Jose usually costs between $350 and $1,800 depending on what’s actually wrong once we get up there, and most standard repairs are finished in a single visit. We work on ranch homes in Berryessa, hillside properties in Evergreen, and everything in between, so the crew that shows up already knows your roof’s pitch, your neighborhood’s permit layers, and what the last storm likely did to it. If you’ve got a leak, missing shingles, or a valley that’s been patched with sealant one too many times, call (743) 200-8347 and a live person will answer. Not a voicemail. A person.
Grant Whitlock leads our Bay Area dispatch team, and every San Jose job starts the same way: we send you the technician’s name and photo before they arrive, they badge in with photo ID at the door, and you get a written price before a single nail comes out.
Why Mercer Roofing Is San Jose’s Preferred Roof Repair Company
We founded Mercer Roofing in 2000 as part of the Threshold Group family, and the standard hasn’t moved since: background-checked, identity-verified technicians in clean uniforms with photo ID badges, on every visit, no exceptions. San Jose homeowners tell us that’s the reason they call us instead of the next name on the list. You know exactly who’s walking up your driveway before they ever get there.
Our reviews from San Jose customers keep coming back to the same three things: the technician showed a badge, the price didn’t move, and the work held through the next rainy season. That last one matters here. San Jose’s concentrated winter storms expose bad repairs fast, and the 365-Day Done Right Promise means if our repair doesn’t hold, we come back and make it right. On our dime, not yours.
Response time to San Jose neighborhoods including Blossom Hill, Alum Rock, and Naglee Park is typically same-week for non-emergency work, with emergency leak calls triaged immediately. When a roof is actively taking on water, speed isn’t a luxury. We get someone out, get eyes on the problem, and get you a written price before we touch anything.
Commercial Roof Repair in San Jose
Commercial Roof Repair in San Jose means working on low-slope and flat membrane systems across the city’s older commercial strips and office parks, from aging TPO and EPDM to built-up gravel roofs. We handle most commercial repairs in San Jose starting around $950 for targeted membrane patches and drain-collar resealing, with full restoration work pricing higher based on square footage and substrate condition once we open it up. The commercial buildings we see here were mostly built in the same 1950s – 1978 window as the tract housing, and the flat roofs on them are hitting their third membrane cycle.
Membrane and Flashing Repairs
Ponding water is the enemy of every flat commercial roof in San Jose, especially through the November to April storm window. We trace the fault lines back to failed seams, clogged drains, and dried-out flashing at curbs and penetrations, then fix the drainage issue along with the leak. A patch without fixing the ponding is just buying time. Written price first, always.
Drain and Scupper Failures
When a commercial roof drain backs up in San Jose’s winter storms, the failure usually isn’t the pipe. It’s the membrane bond around the drain collar. We reseal, re-flash, and when the surrounding deck has started to rot, we cut it back and replace the section. Every commercial repair comes with the same written guarantee as our residential work, including a free second visit if the repair fails within the year.
Roof Leak Repair in San Jose
Roof leak repair in San Jose starts with finding where the water actually enters, not where it shows up on your ceiling. We trace leaks back through attic spaces, along rafter tails, and under failed flashing, then fix the source. Most San Jose leak repairs run between $400 and $1,400, and the wide range comes down to one thing: what we find when we open the roof up. Decades of UV on low-slope south-facing runs hides decking rot that doesn’t show itself until we pull the shingles.
Valley and Flashing Failures
Valleys concentrate water from two roof planes into one channel, and on San Jose’s 2:12 to 4:12 pitches, they move a lot of water fast. When valley flashing fails or shifts, the leak follows. We strip the valley, inspect the decking underneath, replace damaged panels, and re-flash with new metal before the finished shingles go back on. The repair is written up with a price on the first visit, before work starts.
Hidden Decking Damage
We were called to a Silver Creek ranch home in the Evergreen hills where a storm-driven leak had been “repaired” twice with sealant. When we stripped the failed valley, we found termite-damaged fascia, four soft decking panels, and original 1970s underlayment that had turned to powder. Because the house sits in a Very High FHSZ, we re-decked those runs, installed fire-rated underlayment and ice and water shield at the valley and wall transitions, and re-flashed the penetrations with a Class A assembly before the city’s hillside inspection closed the permit. That’s what a real repair looks like here. It isn’t caulk.
Trusted Brands We Service in San Jose
We install and repair GAF, CertainTeed, Owens Corning, IKO, Atlas, and Tamko roofing products, matching the original shingle whenever possible so repairs blend instead of shouting. For San Jose customers, we keep common Atlas and GAF color matches in stock at our Bay Area dispatch yard, which means faster turnaround than waiting on a distributor order. If your existing roof is one of the manufacturer-recognized systems, we repair it under the same shingle brand’s specs. If you need full Roof Repair help and you’re not sure which material you’ve got, we’ll identify it from the ground.
Common Roof Repair Problems We See in San Jose Homes
- Low-slope ranch roof ponding on 2:12 to 4:12 pitches. San Jose’s post-WWII tract homes, from Berryessa to Cambrian, sit at or below the minimum slope for standard shingles, and ponding water through the November to April storms keeps re-wetting the same seams. Patch repairs fail repeatedly until the drainage is addressed.
- UV-baked south-facing Diablo Range slopes. Inland summer heat spikes into the upper 90s and low 100s, and years of that UV breaks down shingle granules on south-facing roofs faster than you’ll see anywhere near the coast. The mat gets exposed, water wicks underneath, and decking rots silently for years before a leak shows inside.
- Sealant-only repairs hiding bigger damage. We routinely open up roofs in San Jose that have had two or three caulk-and-go “fixes” on the same valley or penetration. Underneath, the underlayment is shot and the decking is soft. The scope expands fast once we actually open it, and that’s why we write allowances into the contract from the start.
- FHSZ material restrictions in the hills. In San Jose’s hillside FHSZ tracts, replacing even a section of decking means the new assembly has to stay Class A fire-rated and triggers an additional city inspection layer on the same permit. Flat-valley jobs in Sunnyvale or Santa Clara never face that layer. Our crews know the dual-compliance drill before we ever set a ladder.
Pricing for Roof Repair in San Jose, CA
Here’s what San Jose homeowners should expect before they call, based on the jobs we price most often. A simple shingle replacement on a valley-floor ranch runs $350 – $700. Leak repair, including tracing the source and re-flashing, typically runs $400 – $1,400. Flat roof patches, depending on membrane type and condition, run $500 – $1,800. The price climbs when we open a roof and find decking rot, failed underlayment, or termite-damaged fascia underneath, because that’s not a patch anymore. That’s a structural repair. We handle that with inspection first and allowances written into the contract, so you approve any surprise in writing before we touch it. The estimate is always free, always written, and always honored. Call (743) 200-8347 to schedule yours.
We Also Serve Cities Near San Jose
Our crews cover the full South Bay. If your home is in Milpitas, Santa Clara, Sunnyvale, or Campbell, you’ll get the same Threshold Verified standard: same background-checked technicians, same badge-at-the-door, same written price before work starts. Whether it’s Roof Repair in San Jose or a few exits north or west, the process doesn’t change. You know who’s coming, and you see the price before anything gets touched.
Serving San Jose, CA - Our Local Coverage Area
We’re based in the San Jose 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 Jose
Because homes in those hillside tracts sit inside CAL FIRE-designated High and Very High Fire Hazard Severity Zones, which triggers a second inspection layer and Class A fire-rated material requirements on the same permit. A valley-floor Sunnyvale roof never faces those restrictions, so the job is simpler and moves through permitting faster. Our pricing reflects the additional materials, the extra inspection, and the time it takes to do it right, and it’s all written out before we start. Call (743) 200-8347 for a free estimate on your specific home.
Not correctly, no. At 3:12, you’re right at the lower edge of what standard architectural shingles can handle, and if the underlying decking or underlayment is compromised, shingling over it just seals the problem in. We’ll inspect first, tell you exactly what needs to come off, and write the price before any work starts. The fix on a low-slope Berryessa roof often means improving the underlayment and addressing drainage, not just replacing shingles. Call for the inspection and a written line-item quote.
Decking rot, termite-damaged fascia, and failed underlayment on 1950s – 1970s tract homes. Those roofs are hitting their second or third replacement cycle, and decades of UV on the valley floor have done damage that doesn’t show from the ground. Two prior sealant-only repairs are often the tell. We write allowances into the contract so when we find something, the price for fixing it is already approved and in writing. You’ll never get a surprise invoice. Call (743) 200-8347 to schedule the inspection.
Yes. We repair flat and low-slope commercial systems across San Jose, including TPO, EPDM, and built-up gravel roofs. Drain collars, membrane seams, and flashing at curbs are the most common failure points on San Jose’s older commercial stock, and most targeted repairs start around $950. Written guarantee on every commercial job, same as residential. Call for a written quote on your property.
Because we don’t seal over the problem, we remove it. We open the roof, inspect the decking and underlayment, replace what’s failed, and re-install with proper flashing and drainage. Then we back it with a written 365-day guarantee. If the repair fails within a year, we return and fix it free. That’s the Done Right Promise, in writing, every time. Call (743) 200-8347 to schedule your free estimate and get the exact scope for your roof.
When you’re ready to talk about your roof, call (743) 200-8347. A live person answers, we send your technician’s name and photo before they arrive, and you’ll have a written price before the first nail goes in. That’s how Mercer Roofing works in San Jose.
Written by Grant Whitlock, Owner at Mercer Roofing, serving San Jose since 2000.