IKO Underlayment & Deck Repair Nationwide

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

IKO underlayment and roof deck repair in Jacksonville typically runs between $850 and $2,400 installed, depending on how much decking has rotted and which underlayment your roof needs. We stock IKO-compatible underlayment on our trucks and can usually complete underlayment replacement and deck repair the same week we inspect it. Most homeowners discover the problem after a leak shows up on the ceiling, or when a roofer points out soft decking during a shingle replacement. The underlayment sits between your IKO shingles and the plywood deck, and when it fails, water gets into places it should never reach. In Jacksonville, that means humidity doing slow, quiet damage for months before anyone notices.

Call (904) 604-7914

We’re an independent roofing company, not affiliated with IKO, but we work with IKO materials regularly and know how their underlayment products behave in Florida heat and rain. Erik Lindgren and our crew have repaired enough IKO roofs in Jacksonville to know what fails first, what still holds up, and when a patch is a waste of your money.

Which IKO Models This Applies To

IKO makes several underlayment lines, and the right choice for your roof depends on what’s already there and what your deck can handle. If your home has IKO Cambridge or Dynasty shingles, they were likely installed over a synthetic underlayment like IKO’s StormShield or a felt product depending on the home’s age. IKO StormShield comes in rolls and has a self-adhering backing, which matters in Jacksonville because our summer heat can cause cheaper underlayments to wrinkle and lose their grip. The compatibility gotcha here: IKO’s self-adhered products need a clean, dry deck to bond properly. If a crew lays StormShield over damp or dusty plywood, it will peel within a season. We’ve seen that exact failure in Mandarin and Riverside homes where the underlayment was installed in a hurry.

For decking, the standard in Jacksonville is 1/2-inch or 5/8-inch CDX plywood or OSB. IKO’s installation guidelines require a minimum 3/8-inch thickness, but Florida code and common sense push most roofs to half-inch or thicker. If your deck is undersized or has begun to delaminate from moisture, the new underlayment won’t matter because it has nothing solid to hold onto. We check deck thickness with a gauge on every repair, not by eye.

When it comes to OEM versus aftermarket, IKO’s StormShield is our default for full underlayment replacement because it’s engineered to work with their shingle lines and holds up to Jacksonville’s heat better than budget synthetics. For small patches, we’ll use a compatible self-adhered product if the deck is sound and the surrounding underlayment still has life in it. You’ll see exactly which product we’re using in your written estimate, with the name and the price listed separately from labor.

Signs Your IKO Underlayment & Deck Repair Is Failing

• Ceiling stains that grow after rain. A brown ring that expands after storms means water is getting past the shingles and the underlayment. By the time you see this in Jacksonville, the deck below is usually soft in at least one spot.
• Granules in the gutters. IKO shingles shed granules as they age, and if you’re finding them in downspouts after every rain, the shingles are losing their protective layer. Once that happens, the underlayment is doing all the waterproofing work, and it wasn’t designed to do that alone.
• Soft or spongy spots on the roof deck. We find these when we walk the roof during an inspection. A healthy deck feels firm underfoot. A water-damaged deck gives slightly. If left alone, that soft spot becomes a hole and the ceiling comes down with it.
• Shingles lifting at the edges along the roof. This can mean the underlayment has wrinkled underneath, often from heat or improper installation. Jacksonville summers are brutal on underlayment. When it wrinkles, it pushes shingles up and creates gaps for wind-driven rain.
• Visible rot at the eaves or near flashing. Peel back the shingle overhang at the roofline and you can see if a deck is delaminating or turning dark. This is the most common place we find rot in Jacksonville, usually from clogged gutters forcing water back up under the shingles.

Replacement Cost & What’s Included

For most Jacksonville homes, IKO underlayment replacement runs between $850 and $1,600 when it’s a simple strip-and-relay on a low-slope section. If the deck needs repairs, add $75 to $120 per 4×8 sheet we replace, and most water-damaged roofs in our area need two to five sheets. A full roof underlayment replacement over the entire house with new decking where needed typically lands between $1,800 and $2,400. Your price is stated in writing before we pull a single shingle.

Every IKO underlayment and deck repair we do includes the tear-off of the affected shingles, inspection of the deck by hand, replacement of any rotted or weakened sheathing, installation of the new underlayment, and re-installation of the shingles. We also include the small things that matter to families: shoe covers at the door, drop cloths through the hallway, a magnetic sweep for stray nails after the work is done, and a photo of the clean-up before the crew leaves. The work is covered by our 365-Day Done Right Promise. If it’s not right, we make it right.

DIY or Call Us?

You can safely watch for soft spots from a ladder if you’re comfortable being on one, but walking a roof in Jacksonville’s heat and pulling shingles to inspect underlayment is a job for someone who does this every day. Roof decks get slick with Florida humidity, and a misstep on a two-story home in San Marco or Avondale is not a risk worth taking. The bigger issue is that underlayment and deck repair is not a weekend fix. It means stripping shingles, cutting out bad wood, and making sure the new underlayment bonds correctly in the heat. If any of that is done wrong, your next leak appears within a year and the repair costs double.

If you already know your IKO roof has underlayment or deck damage, call us at (904) 604-7914. We’ll inspect it, show you what we found, and put the price in writing before we touch a shingle.

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