IKO Underlayment & Deck Repair Nationwide

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

IKO underlayment and deck repair in San Diego typically runs $450 – $1,200 installed, depending on how much decking has rotted and which IKO underlayment your roof needs. We stock IKO-compatible synthetic and felt underlayment on our trucks, and most deck repairs are done same-day once we’ve got eyes on the damage. The usual way homeowners find us is a leak that showed up after a winter storm, or a roofer who peeled back a shingle and found soft plywood underneath.

Call (619) 393-3877

San Diego’s sun is brutal on roofing components. The underlayment, which is the water-shedding layer that sits between your plywood deck and the shingles, breaks down from UV exposure and heat long before the shingles themselves fail. Once it goes, water reaches the deck, and wet plywood rots fast. We’ve pulled up IKO shingles on houses in Clairemont and Chula Vista where the shingles looked fine from the curb, but the deck underneath had the structural integrity of a wet cardboard box.

If you’ve got a leak, a sagging spot, or you’re doing a reroof and the contractor mentioned deck repair, this page tells you what you’re dealing with and what it costs. No surprises.

Which IKO Models This Applies To

This covers every IKO shingle line installed in San Diego County: Cambridge, Dynasty, Nordic, and the Royal Estate line. It also covers IKO’s flat-roof systems where they’re paired with a modified bitumen or torch-down underlayment. The underlayment itself falls into two buckets, and the distinction matters for both price and performance.

IKO’s synthetic underlayment, sold as IKO StormShield or their ArmourGard line depending on the series, is a woven polypropylene sheet. It’s lighter, tears less during install, and handles San Diego’s heat without getting brittle. Felt underlayment, the old #15 or #30 asphalt-saturated paper, is cheaper but breaks down faster under our UV load. If your current roof has felt and it’s leaking, the felt is almost certainly the first failure point, not the shingles.

Here’s the compatibility gotcha most homeowners miss: IKO’s lifetime shingle warranty requires that a registered IKO underlayment be used in the same roof assembly. Mixing an off-brand synthetic underlayment with IKO shingles can void the material warranty even if the shingles themselves are fine. We install OEM IKO underlayment on any covered IKO roof for that reason. On roofs past warranty or flat sections where warranty language doesn’t apply, we’ll offer a quality aftermarket synthetic that matches or exceeds the spec at a lower installed price. You’ll know the price before we touch your roof, either way.

Signs Your IKO Underlayment & Deck Repair Is Failing

• Water stains on ceilings or walls after rain. By the time you see interior staining, the underlayment has already failed and the deck below it is wet. The stain is just the lowest point where gravity carried the water.
• Soft spots or spongy feel underfoot on the roof. Rotted decking loses its stiffness. If a section of roof feels like it gives when walked on, the plywood or OSB underneath is breaking down and will need to be cut out and replaced.
• Shingles that look curled, cupped, or lifting at the edges. The shingles are reacting to moisture trapped underneath them. That moisture means the underlayment isn’t doing its job anymore.
• Granules in the gutter that look like coarse black sand. IKO shingles shed granules as they age, but a sudden heavy shed with no hail is often heat damage on a roof where the underlayment has also been over-baked into brittleness.
• Sagging roofline between rafters. This is late-stage deck failure. The wood has lost enough structure that it’s bowing under its own weight. That’s not a repair you ignore, because the next step is a section of roof pulling away in a wind storm.

Replacement Cost & What’s Included

Here’s what we see in San Diego, based on the homes we work on from La Mesa to Carlsbad and everywhere in between.

What drives the range is how far the rot has spread once we open the roof. What we quote is what you pay: the written price includes deck removal, new decking, new underlayment, reinstallation of your existing shingles where they’re reusable, and all fasteners. Every repair carries a written guarantee through our 365-Day Done Right Promise, and if it fails inside that year, we come back at no charge.

DIY or Call Us?

You can absolutely check a few things yourself, safely. Look in the attic for water staining on the underside of the deck. Check gutters for excessive granules. If you’re comfortable on a ladder, look at shingle edges for curling. Those are all no-risk inspections that tell you whether you need to call someone.

The part that goes wrong as a DIY job is the actual deck replacement. Cutting out rotted sheathing without compromising the roof’s structural diaphragm, matching the new decking thickness to the old, and getting the underlayment lapped correctly so water always drains over, not under, takes practice. A bad underlayment lap is the single most common cause of a “repaired” roof leaking again within a year. And roof work in San Diego means pitched sections over a two-story drop. That’s a place for harnesses and trained people, not a Saturday project.

If the inspection findings point to a real issue, call us at (619) 393-3877. We’ll come out, give you a written price, and explain exactly what we found in plain language before any work starts.

FAQs

Get a Written Price Before Any Work Starts

This is how it works here: you call, a live person answers, Greg Holloway or one of our background-checked technicians comes out, and you get a written line-item price for the underlayment and deck repair before anyone starts pulling shingles. That price holds. Every repair carries the 365-Day Done Right Promise from the Kingswell family of roofing companies, founded in 2000. If the repair fails inside a year, we come back free. That’s been the rule since day one and it doesn’t change depending on how busy the season is.

We’re not affiliated with IKO, which means we’re not here to sell you a specific manufacturer’s line. We’re here to match the right underlayment and deck repair to your roof and your budget. Call (619) 393-3877 to schedule a free estimate. You’ll know the price before we touch your roof.

Written by Greg Holloway, Owner, Tilehurst Roofing San Diego at Tilehurst Roofing San Diego, serving San Diego and nearby areas.