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Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
GAF Underlayment & Deck Repair: The Miami Owner’s Guide
We stock and install GAF-compatible underlayment and deck repair on a regular basis across Miami, and most jobs run between $400 and $1,800 depending on how much decking has rotted and which underlayment your roof system needs. Same-day or next-day installation is common once we’ve inspected the damage. Most homeowners find out their underlayment or decking has failed after a leak shows up on the ceiling, or when a roofing inspection ahead of hurricane season turns up soft spots in the plywood.
Underlayment is the waterproof barrier between your roof deck and your shingles or tile. The deck is the plywood or OSB layer underneath it. When either one fails, water gets into places it was never supposed to be, and Miami’s afternoon thunderstorms make sure you find out fast.
Key Takeaways:
- GAF underlayment and deck repair in Miami typically costs $400 – $1,800 installed.
- We match the correct GAF-compatible underlayment to your specific roof system, not just whatever is on the truck.
- Every repair gets a written price before work starts and a written guarantee before we leave.
- Call (850) 613-1762 and a live person answers, day or night.
Which GAF Models This Applies To
GAF makes several underlayment products, and they are not interchangeable. The three you’ll most often see on Miami roofs are Deck-Armor, FeltBuster, and Tiger Paw. Deck-Armor is a breathable synthetic underlayment, FeltBuster is a high-traction synthetic often used on steeper pitches, and Tiger Paw is a peel-and-stick self-adhered underlayment that seals around fasteners. Each one belongs in a specific place in a GAF roofing system.
Here’s the compatibility gotcha most people miss: if your roof has a GAF Golden Pledge or Silver Pledge warranty, GAF requires specific underlayment-to-shingle pairings to keep that warranty intact. Swapping in a bargain underlayment to save money can void that coverage. Tilehurst Roofing Miami is an independent service provider, not affiliated with GAF, but we install to GAF’s published specifications precisely so your warranty survives the repair. We carry all three major GAF underlayment lines plus quality equivalents from Owens Corning and CertainTeed, so if your home’s system calls for something different, we present the options and the prices before any work begins.
Styles & brands we work with
Signs Your GAF Underlayment & Deck Repair Is Failing
- Water stains on ceilings or walls after rain. This is the classic first symptom. It means water has already passed through the shingles, the underlayment, and often the deck. By the time you see the stain, the damage underneath is usually bigger than the stain suggests.
- Soft or spongy spots when walking on the roof. This points to decking rot. In Miami’s humidity, once water sits between underlayment and plywood, the deck starts to delaminate within weeks, not months.
- Shingles or tiles lifting at the edges or blowing off in storms. Underlayment holds the roof’s water-shedding line together. When it degrades, the surface material loses its anchor point and starts to peel.
- Visible underlayment cracks, tears, or sun damage after a storm. Miami’s UV index is brutal. Synthetic underlayment left exposed too long before shingles go on will break down fast.
- Granules from shingles collecting in gutters, paired with leaks. The shingle is failing and so is whatever is underneath it. If the underlayment and deck were solid, a few missing granules wouldn’t be causing water inside the home.
Replacement Cost & What’s Included
For a localized repair, expect these installed ranges in Miami:
- Underlayment section replacement (small area, 1 – 3 squares): $400 – $900
- Deck repair, replacing rotted plywood or OSB (per sheet): $180 – $320 installed, including underlayment over the new deck
- Combined underlayment and deck replacement on a typical repair area (2 – 5 squares): $800 – $1,800
What drives the range: how many sheets of decking have to come out, whether the roof has tile or shingles on top (tile removal and reset adds labor), and which GAF underlayment the system requires. You get a written line-item price before we touch the roof, and the written guarantee is delivered before the crew leaves the property. If that repair fails inside the guarantee period, we come back and fix it at no charge under the 365-Day Done Right Promise. That’s not a verbal promise. It’s paper.
See the difference
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After
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AfterDIY or Call Us?
What you can safely do: inspect from the ground with binoculars, check your attic for daylight coming through the roof deck, and look for water stains on the underside of the plywood. That’s honest reconnaissance. What you should not do: climb onto a two-story Miami roof, peel back shingles, and start cutting out rotted decking on your own. A roof deck repair means working at height, on a sloped surface, and once the underlayment is opened up, any exposed area is vulnerable to the next thunderstorm. A half-finished deck repair that gets rained on is worse than the original problem, because now the water entry point is wide open.
If you find soft decking or water staining, call (850) 613-1762 and we’ll inspect it and put the price in your hands before any work starts. Greg Holloway has been repairing roofs across Miami for years, including plenty of old barrel-tile homes in Coral Gables, and he’ll tell you plainly whether you need a small patch or a full section replacement. Know the price before we touch the roof – that’s the only way he knows how to work.
FAQs
GAF synthetic underlayments carry a limited warranty and are built to outlast the shingles above them, but Miami’s combination of UV exposure, high humidity, and hurricane-driven rain shortens real-world lifespan substantially. Underlayment that sits exposed to Florida sun for more than a few months before shingles are installed will degrade prematurely. In our experience, underlayment failure in Miami is almost always tied to a previous installation that left it exposed too long, or to water getting under the shingles around penetrations and edges. Call (850) 613-1762 for an inspection if your roof is over 12 years old and you’re seeing the warning signs.
Yes, when the deck itself is still structurally sound. We replace the damaged underlayment section, properly lap the seams with the existing material, and reinstall the surface. But if the decking underneath is rotted, delaminating, or too thin, patching over it just hides the problem. We’ll tell you which situation you have before quoting, and the written price covers exactly the work we recommend. For a free evaluation of your specific repair, call (850) 613-1762.
Most repairs take four to eight hours from setup to cleanup, depending on how much decking comes out and how many layers of material sit on top of it. Tile or metal roofs add removal and reset time. We schedule at a time that works for you, arrive in the window we promised, and the crew leaves the property cleaner than we found it.
Yes. Our techs carry GAF Deck-Armor, FeltBuster, and Tiger Paw underlayment, plus plywood and OSB decking, on service vehicles so the repair can usually be completed in one visit. We also stock equivalent underlayment from Owens Corning and CertainTeed when a different system or warranty situation calls for it. For a specific question about which product fits your roof, call (850) 613-1762 and we’ll walk through it on the phone.
Contact Tilehurst Roofing Miami
If your GAF underlayment or deck has failed, or you suspect it’s failing, call (850) 613-1762 for a free estimate. A live person answers every call, 24 hours a day, seven days a week. No voicemail, no callback queue. You’ll get a written price before any work starts, material options from GAF and six other manufacturers, and a written guarantee on every repair we complete. That’s the Kingswell Way, and it’s the only way we work.
Written by Greg Holloway, Owner, Tilehurst Roofing Miami at Tilehurst Roofing Miami, serving Miami and nearby areas.