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IKO Home Additions & ADU: The Los Angeles Owner’s Guide
IKO is a roofing and waterproofing manufacturer, not a home addition or ADU builder. If you found this page searching for “IKO home additions” or “IKO ADU,” you’re most likely trying to either add living space to a home that already has IKO roofing products, or you’re planning an ADU and researching roofing brands for it. A home addition or ADU in Los Angeles typically runs $53,100 to $153,400 for an addition, and $106,200 to $259,600 for a full ADU, with IKO shingles or underlayment as one component of that larger project. The short version: we don’t stock “IKO parts” for additions because IKO doesn’t make framing, drywall, or foundation components, but we do integrate IKO roofing and waterproofing into additions and ADUs across Los Angeles, and we can match existing IKO shingle profiles when we’re tying a new roofline into an old one.
Homeowners usually find themselves on a page like this when a roofline tie-in goes wrong, when an addition starts leaking at the seam where old roof meets new, or when they’re planning an ADU and the city is asking for specific roofing specs. If your IKO roof is failing near a recent addition, the problem is almost never the shingle itself. It’s the flashing, the underlayment transition, or the decking seam underneath.
Which IKO Models This Applies To
IKO makes several shingle lines that show up regularly on Los Angeles homes: Cambridge, Dynasty, Nordic, and Marathon. Cambridge is the one we see most often on 1990s and 2000s-era houses where an addition or ADU is now being planned. If you’re matching an existing IKO roof, the color name matters more than the series name. IKO’s “Weatherwood” from 2010 is not the same granule blend as Weatherwood from 2020, and a mismatched bundle will be visible from the street for the life of the roof. We pull a shingle sample from the existing roof and match it against current IKO color swatches before we order, rather than trusting the label on a faded bundle in the garage.
For additions and ADUs, the roofing decision usually comes down to two paths: match the existing IKO shingles for visual continuity, or re-roof the entire structure with a single IKO line so the whole building ages at the same rate. The second path costs more up front but avoids a patchwork roofline. IKO’s own warranty language treats additions the same as new construction, which means the product warranty applies, but workmanship coverage depends on the installer, not the manufacturer. We install with a written scope that names the exact shingle series, color code, underlayment, and fastener schedule so the warranty claim, if one ever comes, has a paper trail.
Styles & brands we work with
Signs Your IKO Home Additions & ADU Is Failing
- Water staining at the seam where the addition roof meets the original house. This is the classic failure point on Los Angeles additions. The old flashing detail gets disturbed during framing, and the new flashing doesn’t lap correctly over the IKO underlayment. Water finds the gap within the first rainy season.
- Granules in the gutter concentrated near the roofline transition. When a new roof plane is tied into an existing IKO roof at a slightly different pitch, shingles at the transition can rub or flex under wind load. The granular loss shows up in the gutter below that specific seam, not evenly across the whole roof.
- Popping or creaking sounds from the ceiling near the addition during hot afternoons. Los Angeles sun hits IKO shingles hard, and if the decking under the addition’s roof section was not spaced for expansion, you’ll hear thermal movement. It’s not the shingle failing, it’s the framing beneath it, and it telegraphs through the roof assembly.
- Curling shingle edges on the south-facing slope of the addition only. The original house may have adequate attic ventilation, but many additions in Los Angeles get built with minimal venting because the ceiling follows the roofline. Trapped heat degrades IKO shingles from underneath, and it shows first on the south face.
- Damp drywall or peeling paint on the wall directly below the new roofline. This points to underlayment failure or a missing drip edge at the eave, not a shingle defect. Water runs under the shingle course and travels down the wall sheathing instead of into the gutter.
See the difference
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AfterReplacement Cost & What’s Included
A home addition in Los Angeles runs $53,100 to $153,400, and an ADU runs $106,200 to $259,600. Those are the project-level numbers, and the roofing component within them usually lands between $9,440 and $23,600 for a full IKO re-roof on a typical addition footprint, or $470 to $2,125 if we’re repairing a failing transition or flashing detail. What drives the spread: the size of the new footprint, whether you’re matching existing shingles or re-roofing everything, the pitch of the new roof, how much new flashing and underlayment is needed at the tie-in, and whether the existing decking is sound or needs replacement sections.
Every quote includes a written, line-item price before work starts. That means the shingle bundles, the underlayment rolls, the flashing stock, the dump fees, and the labor are all on paper. The written scope is the promise; if it is not on the paper, we have not agreed to it yet. The 365-Day Done Right Promise covers every completed project. If something isn’t right, we make it right.
DIY or Call Us?
You can check a few things safely from the ground: look for missing shingles after a wind event, note where granules are collecting in gutters, and check for visible gaps in flashing at the roofline seam. Those observations help you describe the problem accurately when you call. What you shouldn’t do is get onto an addition roof to replace IKO shingles yourself. Steep pitches, the tie-in seam where old and new framing meet, and the risk of opening up more than you intended are all real. I’ve watched a homeowner pull up three shingles to fix a small leak and end up with a torn underlayment seam that leaked worse the following week. Roof work on additions, especially at transition points, is a job for a trained professional with the right fall protection and the right flashing stock on hand.
If you’re in Los Angeles and your addition or ADU roof is showing signs of trouble, call us at (949) 850-9896. A live person answers, 24/7. We’ll schedule a look, put the findings in writing, and give you a price before any work starts.
FAQs
IKO architectural shingles like Cambridge and Dynasty typically last 20 to 30 years on a Los Angeles addition, but the south-facing slope will show age first because of sustained sun exposure and heat buildup. The tie-in seam is the weak point, not the shingle field itself, so expect the flashing to need attention before the shingles do. Call (949) 850-9896 and we’ll tell you honestly whether the shingles have life left or if it’s time to plan a replacement. Estimates are free.
Yes, when the failure is isolated to the flashing, the underlayment seam, or a small section of damaged shingles, repair usually costs $470 to $2,125 in Los Angeles. If the decking underneath is compromised or the IKO shingles are at the end of their service life, replacement is the better spend. Call (949) 850-9896 and we’ll show you what we found, with photos, before you commit to anything.
Most addition roof repairs at the tie-in seam take one day. A full re-roof of a typical Los Angeles addition runs three to five days depending on pitch, decking condition, and weather. We schedule around your family’s quiet hours where possible and leave the site clean, with a photo of the clean-up before the crew leaves. Call (949) 850-9896 for a written timeline on your specific project.
We order IKO shingles, underlayment, and flashing to match your specific project rather than carrying stock that sits in a yard and fades in the sun. That means we can match existing IKO colors and series accurately, including current Cambridge and Dynasty lines. We also work with named-brand partners like KraftMaid, Cambria, and Silestone when the addition includes cabinetry or countertops. Call (949) 850-9896 and we’ll confirm availability and lead time for your project before you sign anything.
Written by Graham Stein, Owner, Elmstead Remodeling at Elmstead Remodeling, serving Los Angeles and nearby areas.
