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 Roof Installation in Torrance: What to Know First
Owens Corning roof installation in Torrance typically runs $11,000 to $22,000 for a full tear-off and replacement on a standard single-family home, with most projects completed in 3 to 5 working days once materials arrive. We’re an independent Owens Corning service provider, not a factory-owned installer, which means we choose the best Owens Corning system for your roof rather than pushing whatever the manufacturer wants to move. If you’re weighing Owens Corning against other brands or wondering what your existing Owens Corning roof needs, you’ve found the right page. Call (424) 435-5428 to get a written estimate from Grant Whitlock and his crew.

How Owens Corning Products Fail – and How We Fix Them
- Duration Premium and TruDefinition shingle granule loss near the eaves. In Torrance, the morning marine layer leaves roof edges damp for hours longer than the field of the roof. We routinely see granule stripping along the bottom three courses of Duration shingles on homes within a mile of the coast, where moisture softens the asphalt bond and wind accelerates the loss. When we install, we add a wider starter strip and a full row of ice-and-water shield at the eaves so the first shingle course sits on a protected edge, not raw decking.
- Oakridge shingle cracking at nail lines on older decking. Oakridge is a solid three-tab line, but if the decking under it has any flex, the nail holes become stress points and hairline cracks run outward. On tear-offs in Torrance’s older neighborhoods, like Old Torrance and Walteria, we frequently find 3/8-inch plywood decking that’s been softened by decades of coastal humidity. We re-deck those sections before laying new Owens Corning shingles, because nailing a warranty-backed system to splintering wood guarantees a short roof life.
- WeatherLock and StormGuard underlayment failures around roof penetrations. Owens Corning’s synthetic underlayments are strong, but the weak point on any roof is the way flashing is layered around vents, chimneys, and skylights. We’ve pulled apart valley flashings on Torrance homes where the underlayment was installed before the metal, so water running under the shingles hit raw decking. Our installs put the metal in first, then the underlayment over it, then shingles, so water always flows over the surface, never under the barrier.
- ThermaCube and AttiCat insulation causing unexpected soffit condensation. This one surprises Torrance homeowners. When Owens Corning insulation is installed without vent baffles, the rising heat meets the cool underside of the roof deck near the eaves and condenses, soaking through and staining the soffits. Grant Whitlock’s crew has fixed several of these around the Del Amo area by correcting the airflow first, then installing the insulation the way Owens Corning’s own spec sheets call for.
- Decking rot hidden under Owens Corning shingles that look fine from the ground. Shingles can look healthy while the plywood beneath them is turning to sponge. In Torrance, the west-facing slopes catch the brunt of ocean wind and rain, and any gutter overflow compounds the problem. We open a section of the roof before we ever give you a final number, so there’s no surprise line item for decking replacement three days into the job.
Styles & brands we work with






Our Owens Corning Roof Installation Process
- 1
Call and write-up. You call (424) 435-5428. A live person answers. We set a time for the visit, and before our technician arrives, you get their name and photo by text or email. They arrive uniformed and show you a photo ID at the door.
- 2
Roof read. We get on the roof with a moisture meter and inspect the decking in multiple places, not just the obvious ones. Grant insists on opening a few shingles to see what’s actually under them. The number we quote is the number you pay.
- 3
Written estimate. You receive a line-item price covering tear-off, decking repairs known at that point, underlayment, shingles, flashing, vents, cleanup, and disposal. No work begins until you approve it in writing.
- 4
Tear-off and re-deck. We strip the old roof to the deck and replace any plywood that doesn’t pass our moisture and flex test. You see what we see, in photos we show you before we cover it up.
- 5
Installation. We lay Owens Corning’s system in the order the manufacturer specifies: drip edge, underlayment, flashing, starter strips, shingles. We follow spec because warranty claims get denied when installers get creative.
- 6
Inspection and handoff. We walk the job with you, show you the flashing details, the clean gutters, and the magnet-swept driveway. You get a written guarantee on our workmanship for 365 days, and if anything’s not done right, we make it right.
See the difference
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After
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AfterWhat Owens Corning Roof Installation Costs in Torrance
| Scope | Price Range | Notes |
|---|---|---|
| Full tear-off + re-roof, single-story, 1,200 sq ft | $11,000 – $15,000 | Oakridge or Duration shingles, basic underlayment |
| Full tear-off + re-roof, two-story, 2,500 sq ft | $18,000 – $22,000 | Duration Premium, upgraded underlayment |
| Decking replacement (when found) | $65 – $85 per sheet | Confirmed at tear-off, shown to you before install |
| Skylight flashing replacement | $350 – $700 each | Depends on make and condition |
| Trash, haul-away, and disposal | $700 – $1,400 | Includes dumpster and magnet sweep |
What moves the price: the roof’s square footage, pitch, number of penetrations, and what we find under the shingles. A two-story home near the Del Amo corridor with four skylights and a steep pitch lands on the higher end. You’ll never get a surprise change order from us. Call (424) 435-5428 and we’ll put a specific number in writing for your roof.
Why Torrance Homeowners Call Mercer Roofing Co Torrance for Owens Corning Work
We built this company on the belief that you shouldn’t have to gamble when a crew shows up at your door. Every Mercer Roofing Co Torrance technician is background-checked, identity-verified, badged with a photo ID, and their name and photo are sent to you before they arrive. That’s the Threshold Verified standard we’re contractually held to, and it’s not optional. Our workmanship is covered by a written 365-Day Done Right Promise: if it’s not right within a year, we make it right. The roof is only doing its job when you never have to think about it. When Owens Corning turns out not to be the right fit for your budget or slope, we don’t force it. We install GAF, CertainTeed, IKO, Atlas, Tamko, and Boral, and we’ll tell you straight which one belongs on your house. We’ve been at this since 2000, and Grant Whitlock has run enough Torrance roofs to know exactly how the marine layer, the afternoon wind, and your neighbor’s overhanging eucalyptus tree are going to test the work.
FAQs
No. Owens Corning warranties are administered through their network of certified installers, but the warranty is tied to the product and the installation quality. As an independent Owens Corning service provider, we install to spec to protect your claim. The key is following the manufacturer’s installation instructions, which we do on every job.
Most Torrance homes are completed in 3 to 5 working days once materials arrive. Larger homes or projects with extensive decking replacement can run 7 to 10 days. Weather rarely delays us here, but the unpredictable part is what we find under the old roof.
Duration is Owens Corning’s architectural line with a thicker profile and stronger wind rating, while Oakridge is a three-tab line that’s lighter and less expensive. In Torrance’s coastal wind zones, we usually recommend Duration for slopes that face the ocean and Oakridge for sheltered roofs where budget matters more.
If the decking is sound and the leak is isolated, repair is often the right call. We’ll tell you honestly. A patch on a 5-year-old roof makes sense; a patch on a 25-year-old roof is throwing money away. Call (424) 435-5428 and we’ll give you the real answer for your roof.
Yes. We pull permits through the City of Torrance and schedule inspections as part of the written estimate. The permit cost is included in the line-item quote. Call (424) 435-5428 for an exact number on your roof.
Written by Grant Whitlock, Owner, Mercer Roofing Co Torrance at Mercer Roofing Co Torrance, serving Torrance and nearby areas.