Architectural shingles
Metal roofing
Tile roofing
GAF
Owens Corning
Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Fast, Reliable Roof Repair Across Ontario
Roof repair in Ontario, CA usually falls into two camps: wind damage from Santa Ana events and heat-related shingle failure from triple-digit summers. Most repairs we quote in Ontario run between $450 and $1,800 depending on what actually came loose or gave out. If you’re seeing missing shingles, granules in the gutter, or water staining on a ceiling in your Ontario home, call us at (866) 850-2496 for a straight answer and a free estimate. We know these tracts and we know what fails here, which means we don’t waste your time guessing.

Why Windmill Roof Repair Is Ontario’s Preferred Roof Repair Company
Ontario homeowners call us because we work across seven shingle brands and we don’t have a quota to push any one of them. That means when we walk a roof near the 60 or I-15, we’re matching the repair to what the home actually needs, not to whatever’s sitting in our yard. Ruben Ochoa runs our crew with that same philosophy: show the customer what’s happening, explain the options honestly, and repair when repair is the right call. We also offer roof inspection as a standalone service in Ontario, so you can get an objective look at your roof before signing anything. No pressure, no upsell.
Our Roof Repair team serves Ontario’s 91764, 91761, and 91758 zip codes every week. We know the age of the housing stock, we know the wind patterns off the Cajon Pass, and we stock common replacement parts locally so most repairs get completed same-visit. When Ontario homeowners tell us they’ve been burned by roofers before, we take that seriously. Transparency is the only way to fix that reputation.
Styles & brands we work with






Metal Roof Repair in Ontario
Metal roof repair in Ontario is typically needed on the standing seam and corrugated metal roofs found on a handful of custom homes and commercial-to-residential conversions scattered across the city, particularly older properties near the historic downtown where original metal roofs were installed decades ago. Wind uplift from Santa Ana events loosens metal panel fasteners over time, and Ontario’s summer heat expands and contracts panels, eventually compromising seams and gaskets. Most metal repairs in Ontario run $600 to $2,400 depending on panel replacement, fastener work, or seam resealing.
When Metal Roofs Fail in This Climate
Metal is good at shedding rain, but it’s not immune to wind. The 60 to 80 mph gusts that come through the Santa Ana corridor can lift improperly fastened metal panels at the eaves, especially on older installations with exposed fasteners. We see it most often on the shallow-pitch metal roofs on 1950s homes near downtown Ontario and on low-slope commercial buildings along Holt Boulevard.
Repair Scope We Recommend
We replace damaged panels, re-secure loose fasteners with properly gasketed screws, and re-seal seams with a metal-specific sealant. If the roof is at the end of its life, we’ll tell you honestly rather than layering patch on patch. Repair when you can, replace when you must.
Commercial Roof Repair in Ontario
Commercial roof repair in Ontario covers the low-slope and flat built-up roofs on warehouses, retail centers, and industrial buildings concentrated along the 60 corridor, Milliken Avenue, and Vineyard Avenue. These roofs face a unique local problem: standing water from winter storms combined with UV abuse from Ontario’s relentless summer sun breaks down modified bitumen and EPDM membranes faster than in coastal cities. Typical commercial repairs in Ontario run $800 to $4,500 depending on the size of the damaged membrane area and whether underlying insulation has been waterlogged.
Flat Roof Patching on Commercial Buildings
We regularly patch failed seams, blisters, and membrane splits on Ontario commercial flat roofs. The hot inland sun bakes membrane surfaces to the point where flashing at curbs and penetrations cracks and separates. Catching these before winter rain hits saves building owners from interior water damage and inventory loss.
Wind Damage on Commercial Roofing Systems
Santa Ana winds don’t just strip shingles. They peel back poorly adhered membrane edges and tear flashing at the roofline on commercial buildings across Ontario’s industrial sectors. After wind events, we inspect the entire perimeter and re-secure anything loose. Our team gives building owners a written scope and photos so decisions are based on what we actually found.

Trusted Brands We Service in Ontario
We stock and service repair materials from multiple manufacturers, so you get the right product for your Ontario roof rather than whatever a single-brand contractor happens to carry. We regularly repair and replace shingles from GAF, Owens Corning, and CertainTeed, and we can match existing roofs from IKO or other manufacturers when a repair needs to blend. Seven brands, one crew. For wind-rated repairs on Ontario homes, we often recommend GAF architectural shingles installed with a six-nail pattern rated to 130 mph, because this city’s failure mode is wind uplift first and rain second. We keep common colors and profiles accessible for fast turnaround across Ontario, so you’re not waiting weeks for a material order to arrive.
See the difference
Before
After
Before
After
Before
AfterCommon Roof Repair Problems We See in Ontario Homes
- Santa Ana wind stripping: Ridge caps and field shingles blown off 1970s-90s stucco tracts, especially off the 60 and I-15 where original 3-tab shingle sealant strips have baked away over decades.
- Heat-baked shingle failure: Triple-digit summer days accelerate granule loss and sealant failure, so an Ontario roof can look fine after winter rain and then lose shingles in October’s first wind event.
- Low-slope and flat residential roof leaks: 1950s-60s cottage-style homes near downtown Ontario often have shallow-pitch or low-slope roofs where water ponds and finds its way through worn roll roofing or damaged modified bitumen.
- Code-triggered discoveries: When we open up an older Ontario home’s roof for repair, we sometimes find outdated framing, inadequate sheathing, or failed waterproofing that needs correction before the new material goes on. We price and approve that in writing before doing the work.
Pricing for Roof Repair in Ontario, CA
Ontario repair pricing reflects what we actually find up there. A shingle replacement on a small section typically runs $450 to $850. Flashing repair around a chimney or skylight usually falls between $500 and $1,200. Vent boot replacement is one of the more affordable fixes at $300 to $600. Flat roof patches run $600 to $1,800 depending on membrane type and size. Valley repairs where two roof planes meet run $700 to $1,400. Two things drive cost in Ontario specifically: whether wind damage exposed underlying underlayment or decking, and whether the home’s older framing or sheathing needs correction to meet current code once opened. Call (866) 850-2496 for a free written estimate on your Ontario home, and we’ll give you a line-item scope with no hidden surprises.
We Also Serve Cities Near Ontario
Our crews work across nearby Ontario communities including Montclair, Upland, Chino, and Claremont. If you’re in one of those cities and need a roofer who understands Inland Empire wind and heat, we’ll give you the same straight estimate we give our Ontario customers. Call (866) 850-2496 and we’ll get you on the schedule.
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
Because the wind hits old 3-tab shingles where the sealant strip has already cooked away from years of triple-digit heat. Without sealant, the shingle tab isn’t glued to the shingle below it, so a 60 mph gust slides right under and peels it off. Add near-zero rain for months, and nobody notices the sealant is gone until the wind shows up. Call (866) 850-2496 and we’ll do a wind-damage check on your Ontario roof.
On 1950s and 60s homes near downtown Ontario, we often find undersized rafters or the original spaced sheathing that no longer meets code. On 1970s and 80s tract homes, we find failed underlayment and decking rot that was never addressed because repairs were never done properly. We document everything with photos and give you a written scope before any additional work starts.
We stop and show you what we found. You get photos, a written change order with the exact additional cost, and you approve it before we proceed. We never surprise a homeowner with a bill after the fact. That’s how Ruben Ochoa runs every Ontario job, and it’s why customers trust us on older homes where unknowns are more likely.
For wind-uplift resistance, we often recommend GAF architectural shingles with a six-nail pattern rated to 130 mph, or CertainTeed and Owens Corning equivalents with similar wind ratings. The goal is a shingle that stays put during a Santa Ana event and a fastening pattern that doesn’t rely on sealant alone. Call (866) 850-2496 for a brand recommendation matched to your Ontario home.
Ontario’s summer heat bakes shingles and accelerates granule loss and sealant failure faster than in coastal cities ten degrees cooler. That means a roof in Ontario might need attention a few years earlier than an identical roof in, say, Pomona or Chino Hills. Heat also makes repair materials less forgiving during application, so we time heat-sensitive work to avoid Ontario’s highest-temperature afternoons. For an exact assessment, call (866) 850-2496 and we’ll walk the roof together.
Written by Ruben Ochoa, Owner at Windmill Roof Repair, serving Ontario since day one.