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IKO Home Additions & ADU: The Fresno Owner’s Guide
Home additions and ADU construction in Fresno typically run $45,000 to $130,000 for the full project, and the decisions around IKO roofing and waterproofing components are a meaningful part of that number. Most homeowners don’t come to us looking for an “IKO part” by name. They come to us because a room they added is leaking at a transition point, or an ADU they had built is showing water staining at the roofline where the IKO underlayment or flashing was installed incorrectly. We stock IKO-compatible roofing materials and routinely correct failed installations on additions and ADUs across Fresno, including the Tower District, Woodward Park, and Sunnyside neighborhoods.
What we see most often is not a materials failure. It’s an installation detail that was skipped because the original crew was rushing. The IKO membrane itself is generally sound. The problem is usually where it meets a wall, a window, or a plumbing vent.
Which IKO Models This Applies To
IKO makes a range of roofing and waterproofing products, and the one on your addition or ADU depends on the roof pitch and what the original installer specified. The most common IKO products we work with on Fresno additions are the IKO Armourshake, Cambridge, and Marathon asphalt shingle lines, along with IKO’s self-adhered underlayments like StormShield and GoldShield. Each has different compatibility rules for the valley flashing, drip edge, and ice-and-water shield at the eaves and rakes.
The compatibility gotcha we see repeatedly: IKO’s self-adhered underlayment requires a clean, dry substrate to bond properly. If the original crew laid it over damp plywood or in temperatures below 40°F, it will not have sealed correctly, and that shows up later as leaks at the roof-to-wall transition on a new ADU. Another checkable detail: IKO shingles on low-slope additions (under 2:12 pitch) are a flat-out installation error. IKO’s own published installation instructions require a minimum 2:12 slope for their standard shingle products. Below that, you need a membrane roof, not shingles. We have corrected that exact mistake on several Fresno additions.
Elmstead Remodeling Fresno is an independent contractor and not affiliated with IKO. We choose to stock IKO-compatible flashing, underlayment, and ridge components because they are what a lot of Fresno’s existing additions were built with, and matching the system matters more than mixing brands.
Styles & brands we work with
Signs Your IKO Home Additions & ADU Is Failing
- Water staining at the ceiling-to-wall corner of your addition. This usually means the step flashing where the addition roof meets the main house wall was never installed or was installed backward. Step flashing has to weave between shingle courses, not sit on top of them. The fix means lifting shingles and re-detailing the transition.
- Damp drywall around a plumbing vent on the ADU roof. The IKO pipe boot or collar has a rubber gasket that hardens in Fresno’s summer heat. Five to seven years is a realistic lifespan here, not the fifteen some boxes claim. The seal dries, cracks, and lets water run straight down the pipe.
- Granules collecting in the gutter at the drip edge of the addition. This can be normal wear, but on an addition under ten years old it often signals the shingles were installed over an uneven deck or with the wrong nail pattern. Excess granule loss exposes the asphalt base and shortens the roof’s life in Fresno’s UV-heavy climate.
- A musty smell in the ADU that gets worse after rain. This points to trapped moisture behind the wall, frequently at the roof-to-wall flashing on the addition’s high side. The IKO underlayment may be fine, but if the flashing laps were sealed incorrectly, water gets behind the siding and stays there.
- Visible sagging or waviness in the roofline of an addition. On a low-slope addition, this usually means the decking was not rated for the IKO product used, or there is a ventilation problem underneath. Fresno’s hot attic summers bake the underside of an unventilated roof, which warps the deck and compromises the shingle seal strips.
See the difference
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AfterReplacement Cost & What’s Included
For a full IKO-related repair or re-roof on a Fresno addition or ADU, most of our work falls between $8,000 and $20,000 for a complete tear-off and replacement. A targeted flashing or underlayment correction at the roof-to-wall transition runs $1,500 to $4,500 depending on how much shingle lifting and deck repair is involved. If you’re building a new addition or ADU from the ground up, the full project range in Fresno is $45,000 to $130,000, with the roofing and waterproofing system typically representing 8 to 12 percent of that total.
Every Elmstead Remodeling Fresno project includes a written price before any work starts. Not an estimate that drifts after the crew shows up. A number on paper, itemized, with the IKO product names listed so you can verify the specs yourself. Our crew brings drop cloths, shoe covers, and a photo of the cleanup before we leave. The work is covered by our 365-Day Done Right Promise: if it’s not done right, we make it right.
DIY or Call Us?
Here’s the honest split. You can safely check a few things from the ground: whether shingles are missing or visibly curled at the dripline, whether you see granules in the gutter, whether a pipe boot looks cracked from below with binoculars. What you should not do is get on the roof of a Fresno addition in July when the shingle surface is 160 degrees and the pitch is steep enough to slide. A fall from a single-story addition changes a family’s life. Roof work is not the place for a weekend fix.
If the problem is flashing at a roof-to-wall transition, that requires lifting shingles, cutting and weaving step flashing, and often replacing a section of underlayment. Done wrong, you leak more than you did before. Done right, it is a half-day repair. Call us at (559) 540-8453 and we will put eyes on it, tell you what it actually needs, and give you the written price before anything comes off the truck.
FAQs
In Fresno’s heat, a properly installed IKO architectural shingle on an adequately ventilated roof typically lasts 18 to 25 years. Poor ventilation or low-slope installation cuts that to 10 to 12 years because the deck warps and the seal strips fail early. Call (559) 540-8453 and we’ll inspect your roof and tell you what’s actually going on up there.
Yes, in most cases. If the failing area is a roof-to-wall transition, a valley, or a pipe boot, we can often correct the detail without a full tear-off. The repair cost runs $1,500 to $4,500 in Fresno depending on the area and deck condition, and we’ll give you the written price before we start.
A targeted flashing or underlayment repair typically takes half a day to a full day. A full tear-off and reroof on an ADU takes two to four days depending on size, pitch, and weather. We protect the inside during the work with drop cloths and shoe covers, and we keep tools quiet during nap hours where possible.
We keep IKO-compatible flashing, pipe boots, underlayment, and ridge components on hand for the most common Fresno addition details. If your project needs a specific IKO shingle color or line, we source it directly and include the brand name in your written scope of work. While IKO is the focus for roofing components, we also work regularly with KraftMaid, Cambria, and Silestone products across our kitchen and bath remodels.
Written by Graham Stein, Owner, Elmstead Remodeling Fresno at Elmstead Remodeling Fresno, serving Fresno and nearby areas.
