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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.
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.
Styles & brands we work with
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.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
| Scope | Price Range in Miami |
|---|---|
| IKO shingle replacement, addition roof (500-1,200 sq ft) | $9,440-$23,600 |
| IKO tie-in flashing repair (targeted, 10-20 lin ft) | $1,180-$3,540 |
| Complete IKO roof system, ADU (1,000-1,800 sq ft) | $17,700-$47,200 |
| IKO GoldShield underlayment upgrade | $1.85-$2.40/sq ft |
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.
FAQs
In Miami’s climate, properly installed IKO Cambridge or Dynasty shingles last 18-22 years, with the south-facing slope fading and granule-lossing 3-5 years faster than the north face. The key variable is attic ventilation; an unvented ADU roof deck cuts that lifespan by a third. Call (786) 321-4970 for an exact quote on replacement, estimates are free.
Targeted repair works when the failure is isolated to flashing or a wind-damaged section under 100 square feet. Once granule loss exceeds 30 percent of the field or there are multiple soft deck spots, patching costs more than replacement within five years. We document the condition with photos and give you both numbers in writing. Call (786) 321-4970 for a free estimate.
A typical 1,200-square-foot ADU roof takes two to three days: one day for tear-off and deck repair, one for underlayment and shingle installation, and a half-day for inspection and cleanup. Weather delays in Miami’s summer are common; we build a two-day buffer into every schedule we write. Call (786) 321-4970 to check current lead times.
We stock IKO Cambridge and Dynasty shingles in the five most common Miami colors, plus matching ridge caps, starter strips, and GoldShield underlayment. Less common colors or Marathon Plus series require a one-day order from the Tampa distribution center. Call (786) 321-4970 and we’ll confirm color match before we dispatch.
Rowan Construction Group Miami is an independent contractor and is not affiliated with IKO. We also stock and install components from KraftMaid, Cambria, and Silestone.
Written by Grant Rowan, Owner, Rowan Construction Group Miami at Rowan Construction Group Miami, serving Miami and nearby areas.
