Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Fast, Reliable Roof Repair Across Windsor
Roof repair in Windsor, CA typically costs between $350 and $1,800 depending on what failed, and most of the repair jobs we handle here are done in a single visit. Windsor’s combination of wet Pacific winters, dry 90-degree-plus summers, and fall Diablo wind events through the Petaluma Gap puts real stress on shingle roofs, especially the 25-to-40-year-old tract homes that make up most of this town’s housing stock. We know the roof assemblies on these homes because we work on them every week. If you’ve got a leak, lifted shingles, or water staining on a ceiling, call (743) 200-8347 and a live person will answer, day or night.
Why Mercer Roofing Is Windsor’s Preferred Roof Repair Company
Windsor homeowners call us because we solve the problem most roofers ignore: the stranger-at-the-door risk. Before any technician arrives, you get their name and photo sent to you ahead of the visit. They badged in with a photo ID, wear a clean Mercer uniform, and the price of the repair is in writing before a single nail is driven. That’s the Threshold Verified standard we’re contractually held to, and it’s not optional.
Our Roof Repair team handles everything from missing shingles to full valley rebuilds, and we’ve worked on homes from the older subdivisions off Brooks Road to newer builds east of Highway 101. Windsor’s housing stock is specific: thousands of homes built during the 1980s-to-2000s boom are now at or past the lifespan of their original composition shingles. That means what starts as a small leak on a 1994 Windsor tract home often reveals underlayment that’s also failing. We scope that honestly and give you a written price before work begins.
Every repair carries a written 365-Day Done Right Promise. If the work isn’t right within a year, we come back and make it right, at no charge. And every repair includes a written guarantee, with a free second visit if the repair fails.
Shingle Roof Repair in Windsor
Shingle roof repair in Windsor is the most common service we perform, and it usually means replacing cracked, lifted, or missing asphalt composition shingles before water finds its way to the decking. On Windsor’s older tract homes, the original three-tab or early architectural shingles are frequently brittle from two and a half decades of thermal cycling. Expect to pay between $350 and $900 for a standard shingle repair depending on how many shingles are involved and how steep the roof section is.
A shingle repair only works if the underlayment beneath it is still sound. On a 30-year-old Windsor roof, it often isn’t. We’ll tell you honestly if we find paper-felt underlayment that’s breaking down, because if we just nail new shingles over it, the leak comes back in November.
Shingle Matching and Material Availability
We stock common GAF and Atlas shingle colors in service vehicles so most Windsor repairs don’t wait on a supply order. If your roof is an older CertainTeed or Owens Corning color that’s been discontinued, we’ll source the best match available and tell you before we start, not after.
Manufacturer-recognized brands we install and repair include GAF, Atlas, and Tamko. We don’t push exotic materials on a tract-home roof that was built for basic composition shingles.
Leak-Source Tracing on Windsor Tract Homes
The leak you see on the ceiling is rarely where the water is getting in. Windsor’s ranch and two-story tract layouts share a common weak point: valley intersections and sidewall flashing where the roof meets stucco. We trace the water path from the interior stain back to the actual entry point before we quote the repair.
Leak repair in Windsor typically runs $250 to $600 when the problem is confined to a single penetration like a vent boot or pipe collar. If the valley needs to be rebuilt with new ice and water shield, figure $800 to $1,400.
Storm Damage Roof Repair in Windsor
Storm damage roof repair in Windsor is driven less by rain than by wind, specifically the fall Diablo events that barrel through the Petaluma Gap with gusts high enough to lift ridge caps and peel back flashing. Windsor sits directly in that wind corridor. We get calls the morning after every major event, and the damage pattern is almost always the same: lifted ridge shingles, exposed fasteners, and sidewall flashing that’s been pushed back just enough to let rain in on the next storm.
Wind-lift repairs in Windsor run $400 to $1,200, depending on how much of the ridge line is involved and whether the drip edge needs to be re-fastened. When the fastening pattern has failed across a whole roof plane, the repair becomes a partial or full replacement, and we’ll document everything in writing for your insurer.
Diablo Wind Uplift and Ridge Cap Repair
Ridge cap shingles take the brunt of Diablo wind events. They’re at the highest point of the roof, they’re exposed to suction forces from both sides, and after 20-plus years the underlying nails lose their grip. A shingle that looks fine from the ground may have already been lifted and re-seated once or twice.
We re-nail ridge caps to current spec rather than just pressing them back down with roofing cement. If the existing ridge is failing repeatedly, we’ll quote a ridge rebuild with new shingles and proper fastening, and that work comes with the same 365-Day Done Right Promise as any other repair.
Insurance Documentation After Wind Events
Windsor is different from most of Sonoma County on this point. After the Kincade Fire, insurers began demanding documented proof of roofing condition and fire-rated materials before renewing policies. We help by providing written documentation of what was repaired, what materials were used, and the condition of the surrounding roof area.
Trusted Brands We Service in Windsor
We repair and install shingle roofs from GAF, Atlas, Tamko, and other manufacturer-recognized brands, and we keep common components on our service trucks so Windsor jobs don’t stall waiting on parts. Most roof repairs on Windsor tract homes need shingles, underlayment, flashing, and sealant that are readily available from local supply houses and in our own vehicle stock. If your roof is an older Atlas or GAF color that’s been discontinued, we’ll source the closest available match and confirm it with you before ordering. Our goal is to finish the job in one visit whenever the scope allows.
Common Roof Repair Problems We See in Windsor Homes
- Diablo wind damage to ridge caps and sidewall flashing. Windsor sits in the path of fall wind events that push through the Petaluma Gap and cause recurring uplift along roof ridges and where the roof meets second-story walls. The damage may not show itself until the next rain.
- Thermal-cycling cracks on 25-to-40-year-old tract shingles. Windsor’s wet winters and hot, dry summers expand and contract shingles hundreds of times per season. The result is cracking, curling, and eventually water penetration.
- Failed underlayment under shingles that still look okay. Many Windsor homes built in the 1990s have worn-out felt underlayment beneath shingles that appear fine from the ground. When we lift a shingle and find disintegrating paper felt, a true repair means addressing the underlayment, not just the visible shingle.
- Valley seam separation and roof-to-wall flashing leaks. Windsor’s planned subdivisions often feature long valleys and complex roof-to-stucco transitions, and those seams are where we see most interior water damage. Valley sealant dries out and separates over time, which is a gradual process until one strong wind event opens the seam all at once.
Pricing for Roof Repair in Windsor, CA
Here’s what roof repair in Windsor typically costs based on the work we do most often. Shingle replacement runs $350 to $900. Leak tracing and repair at a single penetration runs $250 to $600. Vent boot replacement runs $200 to $450. Valley repair with new ice and water shield runs $800 to $1,400. Flat roof patches start around $500 and go up depending on membrane type and damaged area. Flashing repair runs $350 to $1,000 depending on length and location. And a full ridge cap rebuild after wind uplift runs $700 to $1,500. The main cost variables are roof pitch, accessibility, decking condition, and whether the repair triggers a fire-code upgrade to Class A materials. Every estimate is free, written, and itemized, and the price doesn’t change once work starts. Call (743) 200-8347 to schedule your free estimate.
We Also Serve Cities Near Windsor
Mercer Roofing serves Windsor and the surrounding Sonoma County area, including Healdsburg, Santa Rosa, Sebastopol, and Calistoga. If you’re one town over and dealing with a roof leak, the same written-price, photo-badged technician standard applies across every city we serve. Roof Repair in Windsor remains our core area, but our crews regularly take jobs in the surrounding county.
Serving Windsor, CA - Our Local Coverage Area
We’re based in the Windsor 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 Windsor
It can, and this is more common in Windsor than almost anywhere else in Sonoma County. Since the Kincade Fire, county inspectors and insurers have tightened requirements for Class A fire-rated roof assemblies. A repair that starts as replacing a few shingles can become a code-triggered replacement once the inspector sees the scope. We’ll tell you upfront if your repair is likely to cross that line so you can plan for it. Call (743) 200-8347 for an exact quote on your roof’s condition.
Because many Windsor insurers now require documented proof of Class A roofing materials and completed repairs before renewing or writing a policy. This started after the Kincade Fire and the wave of non-renewals that followed. We provide written material certifications and permit documentation directly to your agent as part of project closeout, so don’t be surprised if your repair ends with paperwork as much as new shingles.
That depends on the condition of your underlayment and decking below the shingles. On a 25-to-40-year-old Windsor composition roof, the visible shingle layer may look salvageable while the underlayment has already failed. We’ll inspect the roof and tell you honestly whether a $500 repair makes sense or whether a full replacement is the better use of your money. The inspection and estimate are free.
Diablo wind events create suction forces that lift ridge caps, pull up sidewall flashing, and open valley seams, often without leaving obvious damage from the street. We inspect for failed fastening patterns and cracked sealant after wind events, then repair what the wind loosened before the next rain finishes the job. Every repair we make after a wind event is documented in writing for your insurer and covered by our 365-Day Done Right Promise.
We price the repair based on actual scope, not on how far out materials are. The written price you’re given before work starts is the final price, and long lead times on specialty materials don’t change that. If a material order extends the schedule, we tell you when we’ll be back and we don’t start the job until we can finish it properly. Full tear-offs typically run $14,000 to $22,000 in Windsor depending on roof size and material grade. Call (743) 200-8347 for a free, itemized estimate on your roof.
Written by Grant Whitlock, Owner at Mercer Roofing, serving Windsor and surrounding Sonoma County since 2000.






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