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 Glendora
Roof repair in Glendora usually runs between $350 and $1,800 depending on what failed and how much decking or underlayment has to be replaced, and most jobs we quote are done in a single day once we’re on site. We know the foothill wind patterns, the older housing stock near downtown, and the tight lots with shared walls that make working in Glendora different from working in Covina or Pomona. Our Roof Repair team covers the full 91740 and 91741 area, from the citrus-era bungalows off Foothill Boulevard to the hillside custom builds climbing toward Big Dalton Canyon. If you’ve got water coming through the ceiling, call (866) 850-2496 and we’ll get someone out to look at it.

Why Windmill Roof Repair Is Glendora’s Preferred Roof Repair Company
We built our reputation in the San Gabriel Valley by doing something most roofers won’t: we repair roofs without steering you into a replacement you don’t need. Ruben Ochoa founded Windmill on a simple principle – the right material for your roof, not ours. That means when we show up to a Glendora home with aging concrete tile on a sun-baked south slope, we tell you whether a targeted tile replacement makes sense or whether the underlayment has given up and a larger repair is the honest call. Glendora homeowners tend to appreciate that, because a lot of them have been burned by contractors who see an older home and immediately quote a full tear-off.
We work across seven shingle brands – GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral – so when we do replace shingles, we’re matching what’s actually on your roof, not forcing whatever brand we happen to have in the yard. That matters on Glendora’s older homes, where a 1970s tract house in the northern 91741 blocks might have a discontinued shingle profile that only one or two manufacturers still make. We also offer roof inspections as a standalone service. No commitment, no pressure. You get a written assessment of what your roof actually needs, and you decide what happens next. Call (866) 850-2496 and we’ll schedule it.
Styles & brands we work with






Emergency Roof Repair in Glendora
Emergency Roof Repair in Glendora usually means one of two things: a Santa Ana wind event just peeled back a section of ridge cap or tile and the decking is exposed, or a heavy winter rain exposed a leak around flashing or a penetration and water is actively getting into the house. Both happen here more often than people expect. The wind funneling out of the San Gabriels hits the north edge of 91741 hard, and the older homes near downtown in 91740 have flashings that have been baking in 100-degree summers for decades. When rain finally does come, the decking soaks it up. Emergency repair typically runs $500 to $1,500 depending on how much material tore loose and whether we need to replace underlayment before getting the roof watertight again.
Wind-Damage Response After Santa Anas
When the fall winds come, we get calls from homeowners whose ridge caps are sitting in the yard and whose windward-facing tile is cracked or shifted. We tarp right away when water is threatened, then do a proper repair once the wind dies down. That means resetting tile, replacing broken ridge cap, and checking that the underlayment didn’t tear where the cap lifted.
Leak Stop and Dry-In
A roof leak over a bedroom or above a finished garage gets a tarp and a same-visit assessment. The repair itself depends on what’s failing – it could be a vent boot, a valley that’s opened up, or flashing that’s pulled away at a wall intersection. We’ll show you what we found, show you what it costs to fix, and start only when you’ve approved the scope.
Flat Roof Repair in Glendora
Flat Roof Repair in Glendora covers the low-slope sections on a lot of the mid-century homes in 91740 and 91741 – patio covers, carports, and room additions that were built with rolled roofing or modified bitumen. The San Gabriel Valley sun is brutal on these surfaces. Temperatures on a flat roof in a Glendora summer can hit 140 degrees and that bakes the asphalt, opens seams, and causes the kind of thermal expansion that pulls flashing loose at the walls. Then a rare heavy rain comes and water ponds where the roof has sagged. A typical flat roof patch in Glendora runs $450 to $1,200, depending on the size of the failed area and whether we need to cut out wet decking or can repair over sound substrate. We work on a lot of these on patio roofs attached to the old bungalows near the historic downtown, where the original flat sections are now 40 or 50 years old.
Seam Failures and Ponding Areas
Flat roofs fail at the seams first. We’ll inspect where the sheets lap, where the roof meets the parapet or house wall, and anywhere water tends to sit. A ponding area that holds water for days after rain is a weak point – we’ll often add a tapered patch or re-slope a small section so water drains instead of soaking in.
Scuppers, Drains, and Wall Flashings
On older flat roofs, the scupper or drain is often the first thing to clog or separate and then water backs up under the roofing membrane. We clear the drain, reset the flashing, and repair the membrane around the penetration. If dry rot has set into the fascia or edge board behind the flashing, we’ll cut that out and replace it before re-flashing.

Trusted Brands We Service in Glendora
Because we’re not tied to one manufacturer, we repair what’s already on your roof. On Glendora homes that means GAF and CertainTeed architectural shingles on a lot of the tract houses, Owens Corning on plenty of the 1980s and 1990s builds, and IKO on some of the newer hillside custom homes. We keep common local stock – shingle colors, ridge cap profiles, vent boots, and flashing – so when we quote a repair we can often complete it that same week without waiting on a specialty order. If you’ve got a discontinued shingle color on an older home, we’ll source a match rather than convincing you to reroof the whole thing. Repair when you can, replace when you must.
See the difference
Before
After
Before
After
Before
AfterCommon Roof Repair Problems We See in Glendora Homes
- UV-baked concrete tile cracking. The south-facing and west-facing slopes on Glendora homes take a beating from 90-100°F summers and intense sun reflection off the foothills. Tile gets brittle, hairline cracks widen, and water eventually reaches the underlayment beneath.
- Ridge caps sheared loose by Santa Ana uplift. Homes on the north edge of 91741 backing up to the wildland interface get the worst of it. The wind comes over the ridge, presses into the roof, and lifts cap tiles on the windward slopes. We’ll reset them and often upgrade the fastening so the next wind event doesn’t do the same thing.
- Flashing gaps at walls, chimneys, and penetrations. Thermal expansion from the hot, dry climate works flashings loose over years. A 1960s tract home near Citrus Avenue may look fine from the ground, but the flashing at the chimney or the wall intersection has pulled a quarter inch and water’s getting behind it during heavy rain.
- Animal intrusion through wind-damaged edges. Raccoons and squirrels along the foothill edge use torn soffit, fascia, and roof edges as an entry. We regularly find nests inside attics near Big Dalton Canyon and in the older 91740 bungalows, usually after a wind event opened a gap and the animals took advantage of it.
Pricing for Roof Repair in Glendora, CA
Expect to pay $350 to $650 for a vent boot replacement or a small flashing repair, $450 to $1,200 for a flat roof patch, $500 to $1,500 for wind-damage repair after a Santa Ana event, and $800 to $1,800 for a larger leak repair that involves decking replacement, underlayment work, and shingle or tile reset. What moves the number is access, decking rot, and whether we’re working on a two-story hillside home or a single-story bungalow with street staging. We’ll give you a written line-item quote before work starts, and the price on that quote is the price you pay. Call (866) 850-2496 for a free estimate and we’ll walk you through what we found.
We Also Serve Cities Near Glendora
Windmill Roof Repair is based in Orange and serves the San Gabriel Valley consistently. Beyond Glendora, our crews are regularly on jobs in Azusa, Citrus, Covina, and Irwindale. Each city has its own building quirks – Covina has more flatland tract housing, Azusa shares the foothill wind exposure – and we adjust how we quote and stage accordingly.
Serving Glendora, CA — Our Local Coverage Area
We’re based in the Glendora 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 Glendora
Yes, some homes in the 91740 historic downtown blocks fall under the Glendora historical or overlay district guidelines, which can require design review for exterior changes, including roofing materials and colors. If your roof is a contributing structure, you may need approval before we change the shingle profile or tile type. We’ve worked through this on citrus-era bungalows and can tell you early whether your project needs review. Call (866) 850-2496 and we’ll help you figure out the process.
The Santa Ana winds funnel out of the San Gabriels and hit the north edge of Glendora with sustained uplift that flatland roofers in Covina or Pomona rarely see. Ridge caps are the first thing to catch that upward pressure, and if they were originally set with standard fastening they’ll lift at the first big event. We reset them with upgraded mechanical fastening and adhesive on windward slopes, which stops the repeat cycle. Call us for an inspection before the next wind season.
We stage materials on the street or in a single designated area of the driveway, never in the neighbor’s access path, and we give notice before starting work on a party wall. On citrus-era bungalows with narrow side yards, we haul waste out by hand rather than dropping it into a shared space. We sweep the site every evening, keep nails out of shared driveways, and leave the neighbor’s side of the wall clean. Site access does affect the quote – if we’re staging on the street and walking materials through a gate, that’s priced into the estimate honestly.
Our quotes cover materials, labor, site staging, waste removal, and any flashing or underlayment needed to make the repair watertight. Compare bids by looking at the line items – is the other roofer including underlayment replacement, or just shingles? Are they matching the existing material, or swapping in whatever they have? We give you a written quote with a defined scope, and if we find rot or hidden damage once the roof is open, we’ll show you a photo and get your sign-off before any additional cost. Call (866) 850-2496 and we’ll send someone out to bid it properly.
Glendora sits directly at the base of the San Gabriel Mountains, with the Angeles National Forest immediately above, and ember exposure from wildfires is a year-round concern. The city’s position along the San Jose/Glendora and Verdugo/Cucamonga fault systems also means seismic resilience factors into roof assembly choices. Repairs here need Class A fire-rated underlayments and materials, where a flatland roofer a few miles south would never even raise the question. We default to Class A assemblies on every Glendora repair without you having to ask.
If your roof is leaking, lifting, or showing its age, call (866) 850-2496 and we’ll schedule a free estimate. We’ll inspect the roof, tell you what’s actually wrong, and give you a written quote you can hold us to.
Written by Ruben Ochoa, Owner at Windmill Roof Repair, serving Glendora and the San Gabriel Valley.