Metal roofing
Architectural shingles
Tile roofing
GAF
Owens Corning
Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
GAF Flashing Replacement: The Fort Worth Owner’s Guide
GAF flashing replacement in Fort Worth typically costs between $350 and $950 installed, depending on which flashing has failed and how much decking repair is needed around it. We stock GAF-compatible flashing profiles on our trucks, and most replacements are completed in a single visit once we’ve walked the roof and confirmed the measurements. Homeowners usually discover the problem after a hard North Texas storm, when staining shows up on a ceiling or paint starts bubbling near a wall line. The flashing is the metal barrier where roof planes meet walls, chimneys, valleys, or pipe penetrations. When it corrodes, lifts, or tears, water gets past the shingles and follows the framing down into the house. By the time you see the stain, the flashing has been failing for a while.
Which GAF Models This Applies To
GAF flashing integration spans most of their residential shingle lines, including Timberline HDZ, Timberline UHDZ, Royal Sovereign, and the Grand Sequoia series. The flashing itself is not tied to the shingle model the way a starter strip might be. What matters is the profile and metal gauge, and GAF’s system is engineered around specific drip-edge geometries and valley configurations that differ from what Owens Corning or CertainTeed specify for their own systems. If you have a GAF roof, we match the flashing material and profile to GAF’s spec rather than grabbing whatever 24-gauge stock is on the truck. OEM GAF flashing is milled to their published dimensions and carries their finish warranty. Quality aftermarket flashing from a reputable metal fabricator can match or exceed that lifespan in Texas conditions, but the gauge must be right: 24-gauge or heavier for exposed headwall and chimney flashing, and we never install anything thinner in Fort Worth. If you still have GAF installation documents, the flashing profiles are listed in the cut sheet. Most homeowners don’t, which is why we measure by hand before ordering anything.
Styles & brands we work with
Signs Your GAF Flashing Replacement Is Failing
- Water staining on ceiling corners or along exterior walls. This is the classic sign that step flashing or headwall flashing has lifted or corroded where the roof meets a vertical surface. The water travels down the wall framing before it shows up on drywall.
- Lifting or curling counter-flashing at the chimney base. Fort Worth’s freeze-thaw cycles work metal back and forth. When counter-flashing pulls away from the mortar, water gets behind the step flashing and soaks the decking beneath the shingles.
- Dark streaks or moss growth at valley intersections. Valley flashing channels a lot of water during Texas downpours. If the valley metal is rusted through or the underlayment beneath it has degraded, you’ll see moisture-loving growth or staining at the low point.
- Granule loss and bare spots in shingles adjacent to flashing. Flashing gets hot, and the shingles pressed against it bake faster. If you’re seeing premature granule loss in a straight line along a wall or pipe, the flashing may be transferring heat badly or letting water wick underneath.
- Exposed nails or visible gaps where the flashing meets the wall. This one you can spot from the ground with binoculars. Texas winds beat on face-mounted flashing, and when fasteners pop, water follows them in.
Replacement Cost & What’s Included
For a Fort Worth GAF-flashing replacement, the price breaks down by location and scope. A single pipe boot or plumbing stack flashing replacement runs $250 to $400. Step flashing along a wall or dormer typically runs $400 to $700. Chimney flashing, which involves cutting a reglet into the mortar, runs $650 to $1,100. Valley flashing replacement lands between $450 and $800. These ranges include the labor, the flashing material cut to spec, sealant, and any minor decking repair we discover once the old flashing is pulled. The biggest price driver is decking rot. If water has been getting past the flashing for a year, the underlying OSB or plywood may need a section cut out and replaced, which adds $75 to $150 per sheet. We put the price on paper before any work starts, and that number does not change at the door. Every flashing replacement carries the 365-Day Done Right Promise: it’s guaranteed in writing for one full year, and if it fails within that period, we come back and fix it at no charge.
See the difference
Before
After
Before
After
Before
AfterDIY or Call Us?
Honest answer: if you’re re-caulking a pipe boot seam or tightening a lifted section of step flashing that hasn’t rusted through, a confident homeowner can do that with roofing cement and careful hand-tool work. What you should not do is pull chimney flashing, cut valley metal, or work on any section of roof with a pitch steeper than 6:12. Flashing work puts you at the edge of the roof, often on a ladder, pulling metal that’s under tension, and the consequences of a slip are real. Travis Oakley has spent the better part of two decades on roofs across the Southwest, and he’ll tell you the same thing he tells his crew: flashing that fails because someone guessed at the profile costs more to fix than doing it right the first time. If water is already inside your house, call us at (682) 900-7902 and we’ll get someone out to look at it before the decking gets worse.
FAQs
GAF flashing installed with proper gauge metal lasts 20 to 30 years in North Texas, though exposed chimney flashing may need attention at the 15-year mark due to thermal expansion and hailstorm abuse. The decking beneath it is often the first thing to fail if the flashing was installed incorrectly. Call (682) 900-7902 if your roof is over 15 years old and the flashing has never been inspected.
Small lifted sections and cracked sealant can be re-secured as a repair, and we’ll do that if the metal gauge is still sound and the decking beneath is dry. If the flashing is rusted through, torn, or has been patched before, replacement is cheaper long-term than repeated caulking. We’ll tell you which one you need after walking the roof, and the price goes on paper before we touch anything.
Most GAF flashing replacements in Fort Worth are done in two to four hours, including removal of the old metal, decking inspection, and sealing the new flashing into the roof system. Chimney work with a mortar reglet cut runs longer, typically half a day. We’ll give you a completion window before the job starts and stick to it.
We keep standard GAF-profile step flashing, pipe boots, and valley metal on our trucks in the most common gauges for Fort Worth homes. Specialty profiles and chimney counter-flashing are fabricated to the measurements we take at your house. We also install flashing systems from Owens Corning and CertainTeed for homes with those roof brands, and we’ll confirm what your roof takes before we order anything.
Call for a Straight Answer on Your Roof
If you’ve got a stain on the ceiling or flashing that’s lifted where you can see it from the ground, we’ll walk the roof, take the measurements, and give you a written price for the repair before any work starts. Tell me what the roof is doing, and we’ll figure out what it needs. Call Brennan Roofing Co Fort Worth at (682) 900-7902 to schedule your inspection. The estimate is free, and a live person answers the phone.
Written by Travis Oakley, Owner, Brennan Roofing Co Fort Worth at Brennan Roofing Co Fort Worth, serving Fort Worth and nearby areas.