IKO Underlayment & Deck Repair Nationwide

IKO Underlayment & Deck Repair: The San Antonio Owner’s Guide

If your IKO underlayment has torn, wrinkled, or started letting moisture through to the deck, we stock IKO-compatible underlayment and deck repair materials on our trucks and can typically get the job priced and scheduled within a day of inspection. Most San Antonio homeowners pay between $450 and $1,400 for underlayment and deck repair depending on how many sheets of decking need replacing and how much of the roof plane is affected. You’ll usually discover the problem after a storm, during a shingle replacement, or when you spot water staining on your ceiling: the shingles look fine from the ground, but the layer underneath has quietly given up.

Call (903) 354-7802

Here’s the thing most people don’t realize: your IKO shingles are only as good as the deck and underlayment beneath them. We see it all over San Antonio, from Terrell Hills to the newer subdivisions off Potranco, where plywood decking bakes in the Texas sun for a decade and starts to delaminate at the edges. Nobody checks the underlayment until it’s already failing. That’s the page you’re on now.

Which IKO Models This Applies To

IKO underlayment is not a one-size-fits-all product. The brand makes several distinct lines, and the wrong match can cause warranty issues down the road. Here’s what we work with in San Antonio:

• IKO StormShield®: A self-adhered ice-and-water barrier used in valleys, eaves, and around penetrations. IKO specifies this on most of their architectural shingle lines in Texas, including Cambridge® and Dynasty®.
• IKO Roof-Fast™: A synthetic underlayment rated for 60-mph winds during install. It’s lighter than felt and resists tearing better. We use this as the primary field underlayment under IKO Cambridge®, Royal Estate™, and Marathon Plus™.
• IKO MVP™: A peel-and-stick base sheet for low-slope areas. If your San Antonio home has a porch overhang or a shed roof section under a 2:12 pitch, this is the part you’re likely dealing with.
• Deck material: IKO requires a minimum 3/8″ plywood or OSB deck for shingle warranty. If your deck is thinner or has rot, we replace with 7/16″ OSB or 1/2″ CDX plywood, depending on the existing deck and local code.

Aftermarket equivalents exist, but we recommend IKO-listed underlayment on IKO roof systems. The compatibility gotcha: IKO’s shingle warranty requires underlayment that meets their covered bituminous or synthetic specification. Installing a cheap off-brand synthetic can void labor warranty claims, even if the shingle itself is IKO. We stock genuine IKO products plus GAF, Owens Corning, and CertainTeed alternatives for side-by-side comparison, but if you’re running an IKO system, we’ll quote IKO underlayment specifically.

Signs Your IKO Underlayment & Deck Repair Is Failing

• Wrinkling or bubbles visible in the attic under the roofline. This happens when synthetic underlayment was installed too loosely or exposed to heat for too long before shingles went down. The wrinkle becomes a gap, and the gap becomes a leak.
• Soft or spongy spots on the roof when walked. The deck has absorbed moisture and lost its structural integrity. Plywood delaminates from the edges, OSB swells at the seams. Both are common in San Antonio after multiple high-humidity summers followed by sudden downpours.
• Water staining on ceilings or walls near exterior walls or around chimneys. This usually means the underlayment at the wall-to-roof transition has failed. IKO calls out flashing details here, and shortcuts during the original install show up years later as slow, persistent drips.
• Shingle tabs lifting or blowing off in normal winds. If the deck below is sound but the underlayment is slipping, you’ll see shingle movement without obvious storm damage. The underlayment isn’t holding the shingle, and the shingle isn’t protecting the deck.
• Granule grit collecting in gutters while shingles still look fine. Granules come off when shingles flex against a damaged deck, not just from age. If the deck is soft, the shingle moves under foot traffic or wind, and the friction accelerates granule loss.

We don’t wave this list at you from a brochure. We walk the roof, we check the attic, and we show you photos of what we find. That’s part of the written estimate, not a upsell performance. If the dog needs to stay inside while we inspect, we’ll coordinate the door schedule with you. If the kids are napping, we’ll keep the ladder work quiet until they’re up.

Replacement Cost & What’s Included

Here’s what we see in San Antonio, and you’ll see your exact number in writing before we start:

• Underlayment replacement only (small area, no deck work): $450 – $750. This covers the tear-off, the new IKO underlayment, and re-installing the existing shingles where possible.
• Underlayment plus 2 – 4 sheets of deck replacement: $800 – $1,400. Deck sheets add material cost and disposal weight, which affects the dump fees.
• Full underlayment replacement on a standard single-family roof: $1,600 – $2,800. That’s a large portion of a re-roof, and if your underlayment is this far gone, we’ll usually recommend considering the full shingle replacement at the same time rather than layering new over old problems.

What’s included: the parts, the labor, the dump fee, shoe covers and drop cloths through the hallway, and a photo of the completed clean-up before the crew leaves. The price we hand you is the price you pay. If we discover more damage once the shingles come off, we stop, we call you, we explain what changed and why, and we get your yes before we proceed. No change orders slipped under the door at dusk. Erik Lindgren has been on too many San Antonio roofs where the previous guy didn’t, and he built Birchbark around not being that guy.

Every job carries the 365-Day Done Right Promise. If the repair isn’t right, we make it right. That’s stamped on the estimate, not whispered in the sales pitch.

DIY or Call Us?

Let’s be honest about this part. You can inspect your attic from inside and spot obvious water stains on the deck. That’s your call to make. You can check your gutters for granule grit. You can look at the eave edges for signs the underlayment is slipping or exposed. All of that is safe ground-level or ladder-free work.

What you shouldn’t do is peel back shingles and start pulling underlayment on a San Antonio roof in July. The exposure risk isn’t just falling, it’s creating a new leak you didn’t have before. We’ve followed enough homeowner repairs where the tarp came loose two days later. Call (903) 354-7802 and let us put eyes on it. If it’s a simple underlayment patch, great, we’ll quote you a simple number. If it’s worse, you’ll know before you spend anything.

We’re an independent San Antonio roofing company, not affiliated with IKO directly, and we’ll tell you if the IKO part or the aftermarket equivalent makes more sense for your roof’s age and condition. A written price and a straight answer, that’s where we start.

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