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Owens Corning Flashing Replacement: The San Antonio Owner’s Guide
Owens Corning flashing replacement in San Antonio typically runs $285 to $640 installed, depending on the flashing type, roof pitch, and how much surrounding shingle work is needed. We stock Owens Corning-compatible step flashing, valley flashing, pipe boot flashing, and wall flashing on our trucks, and most single-area flashing replacements are completed same-day once we’re on site. The way most San Antonio homeowners discover failed flashing is through a ceiling stain after a heavy thunderstorm, or granule-darkened water streaks under the eaves. Flashing is the metal or synthetic material that redirects water where the roof meets a wall, chimney, skylight, or pipe penetration. When it fails, water doesn’t need a big opening to cause real damage, a pinhole under a lifted flashing edge is enough.
Which Owens Corning Models This Applies To
Flashing replacement isn’t tied to one Owens Corning shingle series, it’s tied to the penetrations and transitions on your roof. Whether your home wears Owens Corning Duration, Oakridge, or TruDefinition shingles, the flashing we install is selected to match the profile and exposure of those specific shingles. The compatibility question that matters most is dimensional: Owens Corning Duration shingles have a deeper profile than the older three-tab lines, and if the replacement flashing has a riser too short for that profile, water can lap over the top edge. We measure the shingle butt thickness and exposure before selecting the flashing height, usually 4-inch or 6-inch step flashing risers for Duration, 4-inch for standard Oakridge profiles. As an independent roofing company, we’re not affiliated with Owens Corning, but we work with their shingle lines regularly and spec flashing to factory-treated galvanized steel or aluminum so the metals don’t react with Owens Corning’s granule composition.
Styles & brands we work with






Signs Your Owens Corning Flashing Replacement Is Failing
Flashing fails quietly until water finds its way inside. Here’s what San Antonio homeowners actually see before they call us:
- Ceiling stains near a wall or chimney. Water follows the underside of the roof deck until it reaches a seam or nail hole, then drips. A stain that appears after rain and grows over time points to flashing, not a shingle issue.
- Curled or lifted flashing edges at the roof-wall junction. The thermal expansion and contraction of San Antonio’s hot afternoons and cool nights slowly separates flashing from the wall. Once a gap opens, wind-driven rain gets in.
- Reddish-brown rust streaks below metal flashing. Galvanized flashing corrodes over time, especially where sprinkler water hits it repeatedly. Rust means the protective coating is gone and the metal is thinning.
- Granule loss and staining directly below a pipe boot. Rubber pipe boots dry out, crack, and shrink in the Texas sun. When they do, water runs down the pipe and eats away the shingle granules below it.
- Daylight visible in the attic at penetrations. During strong daylight, look up where pipes, vents, or the chimney pass through the roof. If you see light, water has a path.
See the difference
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AfterReplacement Cost & What’s Included
In San Antonio, here’s what we quote for common flashing replacement jobs:
- Pipe boot flashing (single penetration): $285 – $395 installed.
- Step flashing along a sidewall (up to 10 linear feet): $340 – $520 installed.
- Chimney flashing repair with new counterflashing: $460 – $640 installed.
- Valley flashing replacement (up to 12 linear feet): $390 – $590 installed.
These prices include removing the old flashing, the replacement flashing itself, new roofing cement and fasteners, sealing, and cleanup. The range depends on how much shingle lifting or replacement is required around the flashing, roof pitch (steep roofs cost more because of safety equipment and speed), and whether the decking underneath shows rot that needs repair. Before any work starts, you get a written line-item price. That number does not change unless you approve additional work after we open the area up and show you what we found. Every flashing replacement carries our 365-Day Done Right Promise: if the repair fails within a year, we come back and fix it at no charge.
DIY or Call Us?
Some inspection work is safe for a homeowner: check flashings from the ground with binoculars, look in the attic for light or water trails, and watch for ceiling stains after rain. What we do not recommend is doing the replacement yourself, especially on any roof with a pitch steeper than 6:12. Most flashing failures happen exactly where you have to be to fix them, at the edge, on a ladder, or on a steep plane with a caulk gun in one hand and a pry bar in the other. The materials are affordable, but a bad flashing job is worse than no flashing job because it looks fine from the ground while quietly channeling water into your home. If you’re seeing any of the symptoms above, call (254) 276-4369 and we’ll send a background-checked, uniformed technician with a photo ID badge to take a proper look. You’ll know exactly who’s coming before they arrive, and you’ll have a written price before any work starts.
FAQs
Expect 15 to 20 years from factory-galvanized steel flashing in the San Antonio climate, with rubber pipe boots needing replacement closer to every 8 to 12 years because UV exposure degrades the rubber faster than the metal. If your flashing is older than 15 years and you’re seeing rust or lifted edges, replacement is the right call. For an exact quote and a same-week appointment, call (254) 276-4369 free estimate.
Small gaps at the top edge of step flashing can sometimes be resealed with a high-quality urethane sealant and a new strip of counterflashing, but if the metal is rusted through, torn, or lifted across more than a couple of feet, the only reliable fix is replacement. A sealant patch on failing flashing will keep water out for a season, not a decade. Call (254) 276-4369 and we’ll tell you straight which path makes sense for your roof.
Most single-penetration or sidewall flashing replacements in San Antonio take our crew between two and four hours on site, including bringing the old flashing down, installing the new metal, resealing, and cleaning up with a magnet sweep for loose fasteners. Chimney flashing and valley flashing take longer, usually a full morning, because there’s more shingle work involved. Call (254) 276-4369 and we’ll give you a firm window before we start.
We stock factory-galvanized steel and aluminum flashing that’s compatible with Owens Corning’s shingle profiles, along with rubber-polymer pipe boots and synthetic valley liners on our trucks. We do not stock Owens Corning-branded flashing because Owens Corning doesn’t manufacture flashing as a standalone product line, their shingles are designed to work with third-party flashing materials that meet code and profile requirements. For a roof that’s matched properly and priced honestly, call (254) 276-4369.
Written by Grant Whitlock, Owner, Mercer Roofing Co San Antonio at Mercer Roofing Co San Antonio, serving San Antonio and nearby areas.