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 Ontario
Roof repair in Ontario usually runs between $350 and $1,900 depending on what failed: a simple vent boot replacement sits at the low end, while storm damage across a windward slope and decking repair lands at the top. Most Ontario jobs are done same-week, and we answer the phone with a live person 24/7 when you call (743) 200-8347. If you live near the 60, the 10, or off Euclid Avenue, you already know what a Santa Ana wind can do to a roofline. We do too, because we’re in those neighborhoods every week.
What matters is that the repair is done to a wind rating, not just patched and painted. We’ll get into what that means below, including what a compliant quote should include and what a cheap one quietly leaves out. If you want the short version: call us, get a written price before any work starts, and know exactly who’s showing up at your door.
Why Mercer Roofing Is Ontario’s Preferred Roof Repair Company
We’re part of the Threshold Group family, founded in 2000, and every independent location operates under the Threshold Verified standard. That’s not marketing language; it’s a contract. Our technicians are background-checked, identity-verified, and badged. Before any visit, we send you the technician’s name and photo. When they arrive, they knock in a clean, marked uniform and present a photo ID at the door. You never open the door to a stranger on a Mercer job.
For Ontario homeowners, that’s a real concern. Many of our customers are home alone during the day, or have young children, or are older and want proof of who’s on the property before the boots hit the ladder. We lead with the badge-at-the-door promise because it’s the most concrete thing we do. The second most concrete thing: a written price before any work starts, every time, with no surprises on the invoice.
Every repair we complete in Ontario carries a written guarantee, including a free second visit if the repair fails within 365 days. That’s the Done Right Promise, and it’s included with every job. A live person answers the phone 24/7, not a voicemail, not a call-back form. When wind peels back shingles at 2 a.m., you should talk to a human.
Storm Damage Roof Repair in Ontario
Storm Damage Roof Repair in Ontario is most commonly triggered by Santa Ana wind events, which funnel hot, dry gusts through the mountain passes and into the Inland Empire, peeling back shingles, tiles, and flashing that weren’t fastened to a wind rating. Because Ontario sits directly in this wind corridor, a storm repair here isn’t just replacing what lifted; it’s re-fastening the surrounding area to the manufacturer’s high-wind pattern so the same gust doesn’t tear it off again next season. Most storm repairs in Ontario run $450 to $1,600 depending on slope size, decking condition, and whether underlayment has to be replaced.
Sustained wind events also expose what was already failing: dried-out underlayment, rust-thinned flashing, granule-bare shingles. The wind finishes what the sun started.
Wind-Rated Fastening Pattern
When we repair storm damage in Ontario, we re-nail to the manufacturer’s high-wind specification, which typically means six nails per shingle instead of four and a specific placement pattern relative to the nail line. That’s not optional here. A handyman patch with the original four-nail grid will fail again in the next Santa Ana event, and the insurance adjuster will notice.
Valley and Penetration Flashing
Storm repairs commonly involve flashing at valleys, chimneys, and vent pipes that lifted or separated during high gusts. We replace, not caulk over. Caulk over a lifted flashing joint is a temporary cosmetic fix, and on a windward slope in Ontario, it’s a leak waiting for the next rain.
Metal Roof Repair in Ontario
Metal Roof Repair in Ontario is often about resealing seams, replacing compromised fasteners, and addressing corrosion at panel laps on the low-slope ranch homes and light-commercial metal roofs common through the city’s 1950s to 1970s tracts and along the logistics corridor near Ontario International Airport. Because Ontario’s inland summers routinely exceed 105°F, metal panels expand and contract aggressively, and the fastener and seam sealant system is where failures concentrate. A typical metal roof repair in Ontario runs $380 to $1,200, though panel replacement after severe wind or corrosion damage can push higher.
Seam Re-Sealing and Fastener Replacement
Old metal roofs in Ontario rarely fail because the panel itself is done; they fail at the seams and the screw lines. We clean and mechanically fasten the lap, then re-seal with a UV-stable sealant rated for sustained inland heat. The cheap fix is slapping sealant over a failed seam without cleaning or re-fastening. It lasts a season.
Santa Ana Lift Repairs
Metal panels that have lifted at the eave or ridge after a Santa Ana wind event often need new closure strips, new stitch screws, and sometimes a new eave trim detail. Our crews re-set the panel to the purlin or deck and torque fasteners to spec. Documented wind-rated repairs like these carry weight with an adjuster, especially here where wind damage is an expected event, not an anomaly.
Trusted Brands We Service in Ontario
We repair and install roofing from manufacturers whose materials are built for Ontario’s heat and wind: GAF, Tamko, Boral, plus CertainTeed, Owens Corning, IKO, and Atlas. When a repair requires matching product, we stock the common profiles and colors locally for Ontario customers, which means less waiting on a shipment. Whether it’s an architectural shingle re-nailed to a high-wind pattern or a concrete tile on a 1990s subdivision home that needs its underlayment addressed, we work with the product the manufacturer actually rates for this wind zone, not whatever is on the truck that day.
Common Roof Repair Problems We See in Ontario Homes
- Santa Ana wind lift: Shingles, tiles, or panels displaced on the windward slope because the original fastening pattern didn’t meet the local wind-load requirement. The repair has to include re-nailing the surrounding field, not just replacing the lifted piece.
- Ponding on low-slope ranch roofs: Many of Ontario’s 1950s and 1960s ranch tracts were built with low-pitch roofs that pond water after atmospheric river events. Standing water drives flashing and underlayment failures, and the cheap repair just caulks over the symptom while the decking keeps rotting underneath.
- Granule loss and thermal cracking from 105°F+ summers: Ontario’s radiant heat bleaches granules, accelerates thermal cracking, and dries out underlayment far faster than coastal Southern California. Repairs that don’t address the underlayment and decking fail again within a season.
- Built-up roofing that has aged out: The original built-up systems on mid-century Ontario homes are well past their service life. Many have been capped with architectural shingles whose fastening pattern was never upgraded to the local wind exposure, which is why they fail at the first strong gust.
Pricing for Roof Repair in Ontario, CA
Expect these ranges on typical repairs in Ontario: vent boot replacement, $250 to $400; small flashing repair, $350 to $600; one-square shingle replacement with underlayment, $500 to $850; storm damage repair on a windward slope, $900 to $1,900; metal roof seam and fastener work, $380 to $1,200. What moves the number is decking condition, slope accessibility, and whether the repair has to be brought up to a wind-rated fastening pattern rather than simply patched.
Every estimate is written and line-itemed before any work starts. No one touches your roof until you’ve seen the price and signed off. Call (743) 200-8347 for a free estimate, and we’ll have a technician in Ontario who can put eyes on the problem and give you a number that won’t change once work begins.
We Also Serve Cities Near Ontario
Beyond Ontario, our Roof Repair team serves Montclair, Claremont, Upland, and Rancho Cucamonga. If you’re in one of those communities and have storm damage, a leak, or a repair that just isn’t holding, the same written-price process and Threshold Verified vetting applies. Call (743) 200-8347 and we’ll schedule an estimate.
Serving Ontario, CA - Our Local Coverage Area
We’re based in the Ontario 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 Ontario
Yes. Ontario sits in a Santa Ana wind corridor, and any legitimate re-roof or significant repair has to be engineered to a wind rating, meaning the product carries a wind rating and the fastening pattern matches the manufacturer’s high-wind specification. A cosmetic patch with the original nailing grid doesn’t meet that standard and won’t hold. We document the nailing schedule on every wind-rated repair. For a quote that spells out the wind rating and fastening plan, call (743) 200-8347.
A square is 100 square feet of roof surface, and two bids can look wildly different if one contractor measures the actual repair area and the other rounds up or estimates. Ask both to show the measured area, the nailing pattern they intend to use, the underlayment spec, and the flashing detail. If one bid is cheaper because it omits high-wind re-nailing or new underlayment, it’s not cheaper; it’s incomplete. We’ll walk you through our line-item quote so you can compare apples to apples.
It depends on how long the ponding has been occurring and the condition of the decking underneath. If the decking is sound, a targeted repair may include improving drainage at the low point, replacing saturated underlayment, and re-flashing the penetrations. If the decking is soft or the ponding has been chronic for years, a replacement of the low-slope section is often the honest answer. We’ll cut a small inspection opening if needed, show you photos, and give you a written recommendation either way.
Yes. When your repair is documented with the product wind rating, the nailing schedule, the underlayment spec, and photos, your adjuster has evidence the work meets local wind-load requirements. That often speeds claim approval and can factor into underwriting decisions. We were called out to a mid-century ranch off Euclid Avenue where a Santa Ana event had peeled back the windward slope: the original built-up roof had aged out and been capped with shingles whose fastening pattern didn’t match local exposure. Our crew stripped the slope, added ice and water shield in the valleys and at penetrations, set new drip edge and starter strip, and re-nailed to the manufacturer’s high-wind pattern before flashing and re-decking the ridge vent. The homeowner’s adjuster approved the repair once we documented the nailing schedule and product wind rating.
GAF, Owens Corning, CertainTeed, IKO, Atlas, and Tamko all manufacture shingle lines rated for high-wind zones, with specific models typically rated for 110 mph or 130 mph wind uplift when installed with the manufacturer’s full high-wind fastening pattern. Boral and Eagle tile profiles carry their own wind-rated installation systems for the tile-roofed subdivisions across Ontario. We stock several of these locally and can show you the product spec and fastening requirement before any work begins. Call (743) 200-8347 for a free estimate and a written quote that names the product and the wind rating.
Written by Grant Whitlock, Owner at Mercer Roofing, serving Ontario since our founding in 2000 as part of the Threshold Group family.
For a free estimate on roof repair in Ontario, call (743) 200-8347. You’ll get a real person, a written price before any work starts, and a technician whose name and photo you’ll know before they knock.