Owens Corning
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Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Owens Corning Roofing in San Marcos, TX | Mercer Roofing Co Austin
As a Roofing Company in San Marcos, we provide independent Owens Corning roofing service across San Marcos, TX, for homeowners whose shingles, underlayment, and decking have been through Flash Flood Alley storms. The thing that makes our Owens Corning work here different is simple: we know which of their products hold up on San Marcos roofs and which ones fail early, because we’re on those roofs every week. From Duration shingles on Hill Country slopes to WeatherLock underlayment on historic bungalows, we fix what the weather breaks. Call (361) 202-8874 for a free estimate with a written price before any work starts.
Why San Marcos Residents Choose Us for Owens Corning Service
Grant Whitlock, our owner, learned roofing at Los Angeles Trade-Technical College and has spent decades on everything from flat commercial decks to steep residential pitches. That experience matters when a San Marcos homeowner calls about granule loss on their Duration shingles after a spring hail storm. We don’t guess at what’s wrong. We get on the roof, document what we find with photos, and explain it in plain language.
We’re an independent Owens Corning sales & service provider, not a manufacturer-affiliated or authorized dealer. That independence means we recommend what actually works for your roof, not what a brand program tells us to push. We stock genuine Owens Corning components when a repair must preserve the manufacturer’s wind and impact ratings, but we’ll also tell you when an aftermarket flashing or vent boot will outperform OEM in San Marcos hail and humidity.
Every technician who arrives at your door in San Marcos is background-checked, identity-verified, and photo-badged. We send their name and photo before they arrive. The written price comes before any work starts. The guarantee on every repair is in writing, for 365 days.
Styles & brands we work with
Common Owens Corning Roofing Problems We Solve in San Marcos
- Rapid granule loss on Duration and Oakridge shingles. San Marcos sun is brutal, and combined with large-hail storms, it strips granules fast. Once the fiberglass mat is exposed, UV degradation accelerates and leaks follow. We see this pattern constantly in the 2000s+ subdivisions where these architectural shingles are standard.
- Wind blow-off and tab tearing on Supreme three-tabs. The 1970s and 80s ranch houses throughout San Marcos often still have original Owens Corning Supreme three-tabs. Low-slope roofs in those neighborhoods catch flash-flood wind gusts in a way steeper roofs don’t, and tabs tear loose.
- WeatherLock underlayment failing at valleys and penetrations. This is the most common Owens Corning-specific problem we repair in San Marcos. Factory-installed WeatherLock that wasn’t properly sealed at valleys, vent boots, and skylights gets overwhelmed during Hill Country downpours. The leak is usually at the weak point, not the shingle.
- Nail pops and wind uplift on spaced decking. In the older bungalows east of Texas State, homeowners still have original cedar or three-tab shingles layered over spaced decking. Owens Corning shingles fastened to that decking lift in wind, and water gets underneath. Full redecking is often the only honest fix.
- Hail splits on aged shingles. San Marcos sits in a hail corridor. When hailstones hit Owens Corning shingles that are 15+ years old, splits form along the mat lines. Those splits open up fast and let water straight through to the decking.
Owens Corning Service in San Marcos: What Local Conditions Mean for Your Equipment
Because San Marcos sits in Flash Flood Alley, our Owens Corning repairs routinely focus on sealing valley and penetration flashings, the exact areas where Hill Country downpours overwhelm factory-installed WeatherLock underlayment on the city’s distinctive mix of steep historic roofs and low-slope ranches. A homeowner off C.M. Allen Parkway with a 1960s bungalow has different Owens Corning failure points than someone in a 2005 subdivision off Hunter Road, and the repair should reflect that.
Last spring on a 1960s bungalow east of Texas State off C.M. Allen Parkway, our tech found the original Owens Corning Supreme three-tabs had blown off in a hail storm, leaving exposed felt. We stripped the old shingles, replaced the spaced decking with plywood, and installed a full Owens Corning Duration system with WeatherLock underlayment and new metal valleys. That roof now sheds rainwater even in torrential downpours. That’s what Roof Repair in San Marcos looks like when it’s done right, not patched and prayed over.
San Marcos housing stock runs from early 20th-century pier-and-beam bungalows near the historic downtown and Texas State, to 1970s-80s ranch houses with low slopes, to fast-expanding 2000s+ subdivisions. Each era has different decking, different slopes, and different Owens Corning products on top. A technician who only knows one type of roof will miss problems on the other two.
Owens Corning Models & Products We Service in San Marcos
We service and install the full Owens Corning residential line you’ll find on San Marcos roofs:
- Duration Series (architectural shingles, the most common Owens Corning product in newer San Marcos subdivisions)
- Oakridge (architectural shingles, a mid-grade option we see on 1990s and early 2000s homes)
- Supreme (three-tab shingles, still on many older San Marcos ranch houses and bungalows)
- WeatherLock (underlayment, common on roofs where the original install skipped proper valley sealing)
For repairs, we use genuine Owens Corning components when the manufacturer’s wind and impact ratings need to stay intact. But we’re honest with San Marcos homeowners: in hail and humidity this aggressive, some aftermarket flashing, vent boots, and valley metal outperform what came from the factory. We’ll show you both options and let you decide with real numbers in front of you.
See the difference
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AfterOwens Corning Service Pricing in San Marcos
What you’ll pay for Owens Corning roofing service in San Marcos depends on what we find when we get on the roof. Here are honest ranges based on the work we do most often:
| Service | Typical Range in San Marcos |
|---|---|
| Leak repair (valley or penetration sealing) | $350 – $700 |
| Shingle replacement (small patch, 10-20 shingles) | $400 – $850 |
| Full roof decking replacement (per sheet of plywood) | $75 – $110 |
| Full slope re-shingle with Owens Corning Duration | $3,500 – $7,500 |
| Full roof replacement (Duration + WeatherLock, typical San Marcos home) | $9,000 – $18,000 |
What drives the cost in San Marcos specifically is decking condition. Older homes east of the university with spaced decking usually need redecking before new shingles go on, and that’s a material and labor cost a roof over solid plywood doesn’t carry. Our free estimate includes line-item pricing, photos of what we found, and a written quote that doesn’t change once work starts. Call (361) 202-8874 to schedule yours.
Serving San Marcos, TX - Our Local Coverage Area
We’re based in the San Marcos 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 – Owens Corning Roofing in San Marcos
San Marcos gets intense UV exposure plus frequent large-hail storms. The combination strips granules from Duration shingles faster than in most Texas cities, because the hail fractures the granule bond and the heat then bakes the exposed mat. If you’re seeing granule buildup in gutters within 5-7 years of install, that’s accelerated wear, not a defect. Call (361) 202-8874 and we’ll assess whether it’s cosmetic or structural.
Usually, no. WeatherLock failures in San Marcos typically happen at valleys and penetrations where water got underneath. To properly seal those areas, shingles in the affected zone have to come up, the underlayment gets repaired or replaced, and the shingles go back down. Patching over the top just hides the leak until the next Hill Country downpour. We’ll show you photos of what we found before any work starts.
If your Supreme three-tabs are blowing off in San Marcos wind gusts, the adhesive strip and granule coverage are likely near the end of their life. Patching tabs on a roof that age usually becomes a monthly expense. In most cases, a full replacement with Duration shingles and proper underlayment costs less over five years than repeated patches. Call (361) 202-8874 for an honest assessment with no pressure either way.
Duration is Owens Corning’s best residential answer for San Marcos conditions. It has a woven fabric backing, which helps it resist hail impact, and its granule bond is stronger than the three-tab lines. No shingle is hail-proof, and San Marcos gets the kind of hail that tests every manufacturer. But for the combination of heat and hail this city gets, Duration is the product we recommend most often.
On the older bungalows and pier-and-beam homes around historic downtown San Marcos, the original decking is often spaced boards, not plywood. Owens Corning shingles installed over spaced decking are prone to nail pops and wind uplift. We replace the spaced decking with plywood before installing new shingles. It’s a bigger job and a bigger number on the quote, but it’s the difference between a roof that lasts 25 years and one that fails in five. Call (361) 202-8874 for a line-item quote.
Service Areas Near San Marcos
We serve San Marcos and the surrounding area, including San Marcos service area coverage for all of Hays County. Our crews also work regularly in Owens Corning service in Austin, Owens Corning service in Cedar Park, plus Brushy Creek, Hutto, and Lakeway. If you’re within an hour of San Marcos, odds are we can get to you.
Book Your Owens Corning Service in San Marcos Today
Your roof shouldn’t be something you worry about, that’s what we’re here for. Call (361) 202-8874 to schedule a free estimate. A live person answers, and the written price comes before any work starts.
Written by Grant Whitlock, Owner at Mercer Roofing Co Austin, serving San Marcos, TX. Founded in 2000, part of the Threshold Group family of home-service companies.