IKO Underlayment & Deck Repair Nationwide

IKO Underlayment & Deck Repair: The Fresno Owner’s Guide

IKO underlayment and deck repair in Fresno typically costs $850 to $2,600 installed, depending on how much decking has to be replaced and whether we’re stripping the old roof down to the framing or patching a failed section. We stock IKO-compatible underlayment on our trucks and can match most existing installations same-week, not same-day, because tearing off shingles to expose failed decking is real work. The usual discovery goes like this: a homeowner sees a ceiling stain after a hard rain, or a roofer doing an estimate finds soft plywood under the shingles, or shingles start lifting in a line where the underlayment let go.

Call (559) 785-2160

Most IKO underlayment failures we see in Fresno happen at seams, at penetrations, or along drip edges where the material was installed too tight or exposed to ultraviolet light longer than it should have been. The underlayment is the layer between your decking and your shingles. When it fails, water sits on the wood decking longer than it should, and that wood starts to rot. Deck repair means cutting out the rotted sections and replacing them before new underlayment and shingles go back on.

Which IKO Models This Applies To

The underlayment piece works across most IKO shingle lines, but the compatibility question matters more than people think. IKO manufactures several classes of underlayment: their standard asphalt-saturated felt, their StormShield line for ice-and-water applications, and their synthetic options. If your home has IKO Cambridge, Dynasty, or Nordic shingles over the original IKO underlayment, we can usually match the material class without a problem. If you have IKO’s Armourbase or StormShield self-adhered membrane at the eaves or valleys, that’s a different animal entirely and has to be matched by type, not just by brand.

The gotcha to know: IKO’s self-adhered membranes have a two-part release film, and once that film is pulled, the material has a limited repositioning window. We see DIY attempts where the membrane gets stuck to itself and has to be thrown out. The second checkable detail: IKO synthetic underlayment is manufactured in different roll widths, and the 48-inch rolls don’t always line up with older felt spacing. If your home was built before 2005, there’s a real chance the original underlayment was 36-inch felt, and the lap lines won’t match a modern synthetic roll without some planning. For aftermarket, we use IKO-branded material when we can get it from our supplier, and proven equivalents when we can’t. Both hold up, but we’ll tell you what we’re installing before it goes on your roof.

Signs Your IKO Underlayment & Deck Repair Is Failing

• Shingles lifting along a horizontal line. When underlayment wrinkles or tears, shingles lose their bond and start to flap. The line usually follows the wrinkle, and walking the roof shows a soft or uneven spot underneath. This often appears two to five years after installation because the underlayment was stretched during a hot Fresno afternoon install and contracted later.
• Ceiling stains or attic dampness after wind-driven rain. Underlayment is the water barrier when shingles let go or when rain blows sideways. If water is getting through, the underlayment has a hole, a torn seam, or a bad penetration detail. The leak tells you where the water ended up, not where it started.
• Soft decking felt from the attic. If you push on the plywood sheathing from inside the attic and it gives or feels spongy, the deck has been holding water for a while. Fresno’s dry heat usually hides this because wood dries fast, but the damage from repeated wetting is already structural.
• Granule loss concentrated in one area, not spread evenly. This signals water pooling or running underneath the shingles in that one zone. The shingle surface gets scoured from below. Whenever we tear off a section like that, the underlayment underneath is either missing, paper-thin, or delaminating.
• Rust or water marks on plywood edges visible from a ladder. You can see this at the eaves before you ever climb onto the roof. Stained plywood at the edges means water has been sitting there and draining slowly. It’s the same look as the underside of a wooden planter that stays wet too long.

Replacement Cost & What’s Included

For a targeted repair, meaning we cut out the failed underlayment and rotted decking in one contained area, Fresno homeowners should budget $850 to $1,400. For a full roof deck replacement with new underlayment and shingles on a typical 1,800 to 2,200 square foot Fresno home, expect $7,500 to $14,000, and the underlayment and deck portion of that is usually $2,000 to $4,000 of the total. The range breaks down like this:

• Decking replacement: $2.50 to $4.00 per square foot of replaced plywood or OSB, including tear-out and disposal.
• Underlayment replacement: $0.35 to $0.75 per square foot for synthetic, $0.25 to $0.50 for felt, installed. Self-adhered membrane for valleys and eaves runs $0.80 to $1.20 per square foot.
• Labor and setup: $200 to $600 depending on roof pitch, access, and how much old material has to come off to do the job right.

Every Brennan Roofing Co Fresno job gets the price in writing before any work starts. That price does not move at the door. Our 365-Day Done Right Promise covers the repair in writing for one full year, and if the repair fails in that window, we come back at no charge. That applies to our underlayment and deck work the same as everything else we do.

DIY or Call Us?

There is a honest split here, and I’ll give it to you straight. The part you can safely do yourself is inspection: get into the attic with a flashlight after a rain, look for damp sheathing, and photograph what you see. Tell me what you’re seeing and I’ll tell you what it actually means. That costs you nothing and helps us quote accurately.

The part you should not do yourself is any tear-off work on the roof plane. Underlayment failure is a water management problem, and water travels. You can replace the visible bad section and still have a leak because the failure started six feet upslope and ran down under the felt. Getting to it means cutting out shingles and felt, which means being on a sloped roof in Fresno summer heat with hand tools, and if the decking underneath is rotted, you’re now doing structural work while standing on questionable wood. That’s a dangerous combination, and a wrong step onto a soft sheet of plywood is how people end up in the hospital. Call (559) 785-2160. We’ll inspect it, we’ll show you what we found, and you’ll have a written price before any work starts.

FAQs

Get a Written Price Before Any Work Starts

This is the simple part. You call (559) 785-2160 and tell our live person what you’re seeing. We schedule an inspection. Travis Oakley or one of our background-checked, uniformed technicians comes out, looks at what’s happening, and writes you a price. You don’t pay anything for the estimate, and the price does not change once it’s on paper. Whether it turns out to be a small patch or a full deck replacement, you’ll know the number before anything starts.

Brennan Roofing Co Fresno is an independent roofing contractor and is not affiliated with IKO. We work with their materials because they’re built for the conditions we get out here, but the work and the warranty come from us.

Written by Travis Oakley, Owner, Brennan Roofing Co Fresno at Brennan Roofing Co Fresno, serving Fresno and nearby areas.