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GAF Construction in San Dimas, CA | Mason Remodeling Co West Covina
We provide independent GAF roof repair and replacement across San Dimas, from the flatland ranch homes near downtown to the steep hillside lots north of Foothill Boulevard. The thing that sets our GAF work apart here is simple: we install and repair shingles knowing they’ll face wildfire defensible-space codes, foothill heat that cooks south-facing slopes, and Santa Ana winds that test every ridge cap seal. Call (707) 760-7579 for a free estimate from a crew that works in San Dimas regularly, not occasionally.

Why San Dimas Residents Choose Us for GAF Service
We’ve worked on enough GAF roofs across the Inland Empire to know where these systems fail and why. On San Dimas’s aging ranch homes, that usually means granule loss on southern exposures, wind-lifted ridge caps, and underlayment that was lapped wrong three decades ago. We carry genuine GAF ridge caps, starter strips, and hip-and-ridge shingles so repairs match the original profile. When a roof is beyond patching, we say so plainly. Isaac Pruett grew up in Los Angeles and learned the trade through the construction technology program at Los Angeles Trade-Technical College before spending decades on jobs across the San Gabriel Valley. He runs our crew with a simple rule: if something will cost more or take longer, you hear it before the work starts, not after. For deeper GAF system knowledge, see our GAF sales & service overview.
Styles & brands we work with







Common GAF Construction Problems We Solve in San Dimas
- Wind-driven rain lifting poorly sealed ridge cap shingles. Santa Ana events hit San Dimas foothill neighborhoods hard. When Timberline HDZ ridge caps were never sealed properly, wind gets under them and drives water into valleys and eaves. We see this all the time on homes near San Dimas Canyon Road.
- Granule loss and premature curling on south-facing Camelot II shingles. San Dimas summers are brutal on asphalt shingles. Radiating heat from foothill canyons accelerates granule shedding and curling on Camelot II slopes that face the sun all afternoon. Once the fiberglass mat shows, the shingle is done.
- Nail pops and shingle blow-offs on 1990s and 2000s GAF installations. Steep hillside roofs expand and contract constantly. Old fasteners back out, and the next windstorm peels shingles off in sheets. If your original GAF roof is from that era, this is likely already happening.
- Improperly lapped underlayment at roof-to-wall junctions. Older ranch homes in San Dimas often have stucco walls meeting roof decks with underlayment that was never lapped correctly. Heavy winter rains find those gaps and water migrates behind the stucco before you see a ceiling stain.
- Ember resistance gaps on Class A-required hillside properties. North of Foothill Boulevard, wildfire code requires Class A roof coverings. Older GAF asphalt shingle installations often fail ember-resistance inspection because of gaps at drip edge and underlayment details.
GAF Service in San Dimas: What Local Conditions Mean for Your Equipment
San Dimas is one of the only Los Angeles County cities where wildfire defensible-space rules trigger a Class A roof covering mandate on hillside properties north of Foothill Boulevard. GAF asphalt shingle roofs in those neighborhoods must be inspected for ember resistance, not just leaks. Our crew sees this requirement on every foothill reroof. We adjust drip edge and underlayment installation details to keep homeowners compliant, and we document the work so you have a record when the fire marshal asks. That little detail changes how we install on San Dimas Canyon Road compared to, say, a flatland tract home in Pomona. It is not optional, and we treat it that way. For homeowners who have lived in San Dimas for decades, this is the difference between a roof that passes inspection and one that has to be torn into a year later.
GAF Models & Products We Service in San Dimas
We work on Timberline HDZ, Timberline UHDZ, Camelot II, and Grand Sequoia shake-style shingles, the profiles most common on San Dimas ranch homes and foothill custom builds. We stock genuine GAF ridge caps, starter strips, and matching hip shingles locally so turnaround on repairs is measured in days, not weeks. For roofs out of warranty, we often recommend upgraded synthetic underlayment and ice-and-water shield in valleys. The original GAF accessory specification was fine for its era. San Dimas weather has not gotten gentler since. See our San Dimas service area details for coverage boundaries.
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Here is what GAF roof work costs in the San Dimas market right now:
| Service | Price Range |
|---|---|
| Roof Repair | $400 – $1800 |
| Roof Replacement | $8000 – $20000 |
Repair cost depends on how many slopes are affected, how steep the roof is, and whether underlayment or plywood needs replacing. Full replacement cost is driven by square footage, tear-off labor, accessibility on hillside lots, and whether you choose Timberline HDZ or the thicker UHDZ profile. Every estimate we give is written, line-itemed, and delivered before any work starts. No verbal number that grows later. Call (707) 760-7579 to schedule a free estimate. You should know what you’re getting before we ever pick up a tool.
Serving San Dimas, CA - Our Local Coverage Area
We’re based in the San Dimas 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 – GAF Construction in San Dimas
Yes. Hillside properties north of Foothill Boulevard fall under wildfire defensible-space rules that require a Class A roof covering. GAF asphalt shingles can qualify when installed with the proper drip edge, underlayment, and ember-resistant details. We inspect existing roofs for compliance and document everything on new installations. Call (707) 760-7579 if you need a compliance check before fire season.
In most cases, yes. We carry genuine GAF ridge caps and matching shingle profiles in the colors most common on San Dimas’s older ranch homes. If your original line is discontinued, we’ll show you the closest available match before we order anything. Call (707) 760-7579 and we’ll come look at the slope.
Granule loss in San Dimas almost always traces to intense sun exposure on south-facing slopes and heat radiating from foothill canyons. Once the asphalt binder dries out, granules release. It gets worse every year. If you’re seeing granules in the gutter, the shingles are already aging faster than the manufacturer’s rating. Call (707) 760-7579 for an inspection before winter rain turns a granule problem into a leak.
Ridge cap repair alone is common if the cap shingles lifted or blew off but the field shingles are still sound. We’ll inspect the roof deck and underlayment at the ridge before recommending a repair. If the whole roof is past its service life, we’ll tell you plainly rather than patch it and charge you again next year. Call (707) 760-7579 for a written quote on the specific slope.
For steep hillside lots with high sun exposure and Santa Ana wind stress, the thicker UHDZ profile gives you meaningfully better impact resistance and wind performance. The price difference is real but often less than the cost of one future repair cycle. We’ll give you both line items so you can decide. Call (707) 760-7579 for a written comparison.
Service Areas Near San Dimas
We also cover GAF service in West Covina, GAF service in Pomona, plus Walnut, La Puente, and La Habra. If your roof sits in any of these neighboring markets, we can schedule a free estimate on the same call.
Book Your GAF Service in San Dimas Today
Call (707) 760-7579 and a live person answers, any day, any hour. We’ll schedule your free GAF roof inspection in San Dimas and put a written estimate in your hands before any work starts.
Written by Isaac Pruett, Owner at Mason Remodeling Co West Covina, serving San Dimas since 2004.











