IKO Home Additions & ADU Nationwide

IKO Home Additions & ADU: The Miami Owner’s Guide

IKO-compatible roofing and waterproofing components for home additions and ADUs in Miami typically run $53100-$153400 for a complete addition project, with IKO-specific flashing, underlayment, and drainage parts available for targeted repairs. We stock IKO Cambridge, Dynasty, and Marathon Plus series shingles and accessories for same-day replacement when water intrusion threatens your new living space. Most Miami owners discover the problem after a hard rain, when they spot a water stain spreading across the ceiling of their recently finished addition or notice the ADU’s IKO shingles lifting in the wind corridor between the main roof and the new structure.

Call (786) 321-4970

Which IKO Models This Applies To

IKO’s residential lines each handle the Miami climate differently, and matching the right component matters more on an addition or ADU where the roof plane ties into an existing structure. The Cambridge Architectural shingles, Dynasty with ArmourZone, and Marathon Plus 3-tab are the three series we see on South Florida additions. Check the underside of a loose shingle or the edge of your starter strip for the printed series name and the 12-digit IKO lot code, which tells us the manufacturing date and the exact granule blend.

The compatibility gotcha on additions is the tie-in flashing where the new roof meets the existing wall or roofline. IKO’s pre-formed step flashing works with Cambridge and Dynasty at a 5-inch exposure, but Marathon Plus requires a 4-inch exposure that leaves a half-inch gap if you force the wrong piece. We carry both OEM IKO FastLock and IKO ArmourZone ridge caps, plus aftermarket equivalents from Atlas and CertainTeed where the color match is closer on older IKO lots faded by Miami’s UV. For underlayment, IKO’s GoldShield synthetic underlayment is specced on most ADU permits we pull in Miami-Dade; the alternative is a double layer of 30-pound felt, which costs less upfront but carries a shorter warranty when the inspector reads the paperwork.

Signs Your IKO Home Additions & ADU Is Failing

• Granule loss exposing the asphalt mat. Miami’s UV index averages 6.7 even in winter, and IKO shingles lose granules faster on south-facing addition roofs where the main structure blocks afternoon shade. Once the mat shows, water wicks through in 18-24 months.
• Lifted or cupped shingles at the addition tie-in. The wind accelerates where two roof planes meet, and IKO shingles installed without proper starter strip adhesion peel back first. We see this most on ADUs in Coral Gables and Pinecrest where the setback creates a wind tunnel.
• Rust streaks on the fascia below the IKO drip edge. The galvanized steel IKO drip edge on pre-2019 installations used a lighter gauge that corrodes where salt air concentrates. The rust signals water running behind the gutter, rotting the fascia board.
• Soft drywall at ceiling corners in the addition. IKO’s self-adhered ice-and-water barrier is required by Miami-Dade code at valleys and penetrations, but installers sometimes skip the 24-inch vertical run up the existing wall on a tie-in. Water finds that gap during our summer deluges.
• Interior humidity spikes in the ADU. IKO’s roof system includes ridge venting specified to NFVA ratings; when the ridge cap is mismatched or blocked, the ADU traps moisture. We measure this with a hygrometer during inspection, and readings above 60 percent confirm inadequate exhaust.

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Replacement Cost & What’s Included

The range depends on three factors: whether we can match the existing IKO color lot, how many layers we strip at the tie-in, and whether the Miami-Dade inspector requires a full nailing pattern inspection on the addition. Our quote includes tear-off, deck inspection with photo documentation, IKO-specified underlayment and flashing, and disposal. Under the Haven Standard, the price is written before anyone starts, and no change proceeds without a signed change order. The 365-Day Done Right Promise covers workmanship; IKO’s limited lifetime warranty covers material defect.

DIY or Call Us?

A homeowner can safely check the lot code on a loose shingle, photograph lifted areas from a ladder at gutter height, and verify interior humidity with a basic meter. Do not climb onto the addition roof yourself. The tie-in slope is often steeper than the main roof, and the transition point has no ridge anchor for a safety harness. The real risk is stepping through the soft spot you haven’t found yet.

DIY shingle replacement on an IKO system also voids the wind warranty if the nailing pattern doesn’t hit the 4-nail, 1-inch-above-tab-line spec that IKO requires for 130-mph coverage in Miami-Dade. We’ve had to strip and reinstall homeowner repairs to pass final inspection. Call (786) 321-4970 and we’ll schedule a free estimate with a written price, photo documentation of what we find, and a scope that specifies every IKO component by series. Measure twice, write it down, then build it.

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