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
IKO Underlayment & Deck Repair: The Austin Owner’s Guide
IKO underlayment and roof deck repair in Austin typically runs $350 to $950 for a localized section, with full redecking on larger homes starting around $1,400. We stock IKO-compatible underlayment on our trucks and can usually complete a deck patch and underlayment replacement the same day we diagnose it. Most Austin homeowners discover the problem after a leak shows up on the ceiling, or when a roofer doing a shingle replacement peels back the old layer and finds the decking has gone soft underneath.

What surprises people is how often the underlayment itself is the culprit, not just the shingles above it. In Austin’s heat, underlayment can bake and crack long before the shingles look worn. Once the deck below gets wet repeatedly, the repair stops being a simple shingle swap and becomes a structural fix. We see it most in older Zilker and Hyde Park homes where the original decking predates modern ventilation standards.
Which IKO Models This Applies To
This repair work applies across the IKO shingle lines common in Austin: Cambridge, Dynasty, Nordic, and Royal Estate all sit on the same underlying deck and underlayment system. The shingle model matters less than the underlayment type installed and the condition of the decking beneath it. If your roof has IKO’s Armourbase or GoldShield underlayment, we match the replacement to the original spec so the warranty on the remaining shingles stays intact.
Here’s the compatibility gotcha most people don’t know: IKO underlayment comes in different grades, and the cheaper felt-based products break down far faster in Texas heat than the synthetic lines. If your roof was installed with #15 felt, that underlayment is often the first thing to fail, especially along eaves and valleys where water sits longer. We carry synthetic IKO-compatible underlayment as our default replacement because it holds up better in Austin’s freeze-thaw-and-bake cycles. For the deck itself, standard CDX plywood at 1/2-inch to 5/8-inch thickness is the norm, though some older Austin homes used 1×6 plank decking that needs matching board-for-board rather than sheet replacement.
One thing worth stating plainly: Mercer Roofing Co Austin is an independent roofing contractor, not a division of IKO. We install and repair IKO products alongside GAF, Owens Corning, and CertainTeed, so we’re not tied to pushing one brand over another. If an IKO-specific underlayment makes sense for your roof, that’s what we use. If a different product fits better, we’ll tell you why and quote it honestly.
Styles & brands we work with






Signs Your IKO Underlayment & Deck Repair Is Failing
- Water stains on ceilings or walls after moderate rain. This often means the underlayment has failed at a seam or nail point, letting water through even when shingles look fine. The stain usually shows up days after the rain, once the water has traveled through insulation.
- Soft or spongy spots when walking the roof. Decking that flexes underfoot means the plywood or plank has absorbed water and lost its structural integrity. In Austin, this is most common around chimneys, skylights, and the lower edges of valleys.
- Granules collecting in gutters in odd amounts. Shingle wear is normal over time, but when underlayment is failing, you’ll often see accelerated granule loss in specific areas as the shingles shift and rub against a deteriorating deck.
- Visible sagging between rafters from inside the attic. Look up at the underside of your roof deck. If the plywood bows downward between the framing members, water has compromised the deck. This is a repair that should be scheduled sooner rather than later.
- Musty attic smell or damp insulation near the roofline. Even without a visible leak, trapped moisture from a failing underlayment changes the attic environment. In Austin’s humidity, that moisture leads to mold faster than in drier climates.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For Austin homeowners, expect to pay between $350 and $950 for a typical underlayment and deck repair covering one to three sheets of plywood, including tear-off of the affected shingles, deck replacement, new underlayment, reinstallation, and cleanup. If the damage spans a larger area or requires full redecking, the price climbs accordingly, with whole-roof deck replacement on a 1,800-square-foot home typically landing between $3,500 and $6,500 depending on access and pitch.
Every Mercer Roofing quote is a written line-item price before work starts. You’ll see the deck material, underlayment type, shingle count, and labor broken out separately. No change orders appear after the fact unless you approve additional work in writing. And every repair carries our written guarantee for 365 days, with a free second visit if the fix doesn’t hold.
DIY or Call Us?
You can safely check a few things yourself. From inside the attic, look for damp spots, sagging deck, or daylight coming through gaps. From the ground, note any shingles lifting at the eaves or debris piling up in valleys. Those observations help you talk to a roofer intelligently, and they cost nothing.
But replacing decking and underlayment means pulling up shingles and working on a sloped surface, often with power tools and in Austin’s unforgiving sun. A bad fall off a roof changes a day’s plans into a hospital visit. The part failures we’re talking about here aren’t like swapping a light fixture. If the deck has rot, the repair involves cutting out the damaged section, checking the framing underneath, and installing everything back in the right order so water doesn’t find a new path in. That’s the work we do every week, and we’re glad to walk you through what we find before anything gets torn off. Call (361) 202-8874 and we’ll schedule a time to take a look.
FAQs
IKO synthetic underlayment should last 20 to 30 years in Austin if properly installed and ventilated, but the older felt-based products often need replacement within 10 to 15 years due to our heat and UV exposure. The decking beneath it should last the life of the home unless water gets past the underlayment. Call (361) 202-8874 if you suspect premature failure, and we’ll inspect before recommending a full replacement.
Yes, if the deck itself is still solid, we can remove the affected shingles, replace the underlayment section, and reinstall the shingles. But once the deck is soft or delaminated, patching over it just hides the problem. The written estimate we provide will state exactly what needs replacement and why. Call (361) 202-8874 for a no-cost inspection.
Most localized repairs take four to six hours from setup through cleanup. Larger redecks can run one to two days depending on the roof’s pitch, the weather, and how much decking needs to come out. We’ll give you a time frame in writing before the job starts. Call (361) 202-8874 to schedule your free estimate.
We stock IKO-compatible synthetic underlayment and standard decking materials on our trucks, so most underlayment and deck repairs are completed same-day without a supply run. For unusual deck thicknesses or specialty IKO products, we may need a day to source the right match. Call (361) 202-8874 and we’ll confirm what you need before we arrive.
Grant Whitlock, owner of Mercer Roofing Co Austin, learned the trade at Los Angeles Trade-Technical College and has spent years working on Austin roofs, including the Zilker neighborhood where summer hail keeps every roofer honest. We believe your roof shouldn’t be something you worry about, that’s what we’re here for. When you call, you’ll speak to a live person who can schedule your estimate and answer questions about your IKO roof. Every technician who comes to your door is background-checked, uniformed, and badge-verified under the Threshold Standard, and you’ll see their name and photo before they arrive. Call (361) 202-8874 for your free, written estimate.
Written by Grant Whitlock, Owner, Mercer Roofing Co Austin at Mercer Roofing Co Austin, serving Austin and nearby areas.