IKO Flashing Replacement in Seattle, WA

IKO Flashing Replacement: The Seattle Owner’s Guide

IKO flashing replacement in Seattle typically runs $340-$780 installed, depending on the location and how much surrounding material needs attention. We stock IKO-compatible step flashing, apron flashing, and valley flashing on every Ridgeline truck, and most replacements are completed in a single visit. Homeowners usually discover the problem during our fall inspection season, when water staining appears on ceiling drywall near chimneys, dormers, or wall-to-roof transitions after the first sustained rains return off Puget Sound.

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Which IKO Models This Applies To

IKO’s flashing systems pair with their full shingle catalog, but the critical match points are series-specific. IKO Cambridge, Dynasty, and Nordic lines each use slightly different exposure dimensions, which means the step flashing height must correspond or the water channel misses the shingle overlap entirely. We’ve found the IKO Cambridge AR line, common on Ballard and Phinney Ridge homes from the 2005-2015 reroof wave, often needs 4″ × 5″ step flashing where generic 3″ × 4″ gets substituted by crews cutting corners.

Check your original paperwork for the IKO shingle series name, or look for the printed strip along the shingle bundle edge if you have leftovers in the garage. The flashing itself rarely carries an IKO logo; instead, look for a stamped gauge marking (26-gauge galvanized steel is standard for IKO residential systems) and a baked-on Kynar finish color code that should match your shingle bundle label. We carry both OEM IKO flashing and quality aftermarket equivalents from Sheffield Metals that meet the same 26-gauge spec. The aftermarket runs 15-20% less on material cost and carries the same 25-year finish warranty in Seattle’s marine climate.

One compatibility gotcha we’ve handled repeatedly in West Seattle: IKO’s Armourshake and Crowne Slate premium lines require wider apron flashing at the eaves, 8″ minimum rather than the standard 6″, because of the thicker shingle profile. A crew unfamiliar with IKO’s premium line will install standard flashing and create a lip where debris collects.

Signs Your IKO Flashing Replacement Is Failing

• Water stains on interior ceilings or walls, especially after wind-driven rain. Seattle’s southeasterly winter storms push rain uphill against flashing laps. When the sealant bead behind IKO step flashing dries and separates, water follows the wall plate into the attic rather than shedding to the gutter.
• Rust streaks bleeding down siding or brick below roof-wall joints. IKO flashing uses galvanized steel with a painted finish. Once the Kynar layer cracks from thermal cycling, usually after 18-22 years in our moderate climate, the galvanized layer underneath begins sacrificing itself. Those rust trails mean the flashing is in active failure.
• Lifted or curled shingles directly above the flashing line. Failed flashing lets moisture saturate the shingle underside, causing the fiberglass mat to swell and the tab to curl. In Magnolia and Queen Anne, where homes catch full afternoon sun off the Sound, this accelerates noticeably on south-facing slopes.
• Visible gaps or daylight between flashing pieces at dormer cheeks. IKO step flashing is designed to interleave with each shingle course. If you can see gaps from the ground, the pieces have slipped, the fastening has backed out, or a previous installer used continuous strip flashing instead of individual pieces, which IKO does not recommend.
• Granule accumulation in gutters below wall transitions. This seems counterintuitive, but when flashing leaks, water runs behind the shingle and washes granules loose from the underside. If your gutters show heavy granule deposits localized to one wall section, the flashing above is the first place we check.

Replacement Cost & What’s Included

What drives the range: accessibility (steep pitches above 8/12 add labor time), whether we need to remove and reset surrounding shingles in good condition, and if the underlying wall sheathing shows rot. Our estimate includes the IKO-compatible flashing material, matching color finish, ice-and-water shield underlayment at the transition, shingle reset or replacement as needed, and disposal. The 90-Day Done Right Promise covers the workmanship; the flashing material itself carries the manufacturer’s finish warranty. We quote the full number upfront, and that is the number on the invoice.

DIY or Call Us?

There is an honest boundary here. A homeowner can safely check for the symptoms above from the ground with binoculars, or from an attic with a flashlight, looking for water trails on the underside of the roof deck. What you should not do is climb a ladder to pry at flashing laps or attempt removal yourself.

Flashing replacement requires working at height on a pitched surface, often near wall transitions where the footing is awkward. More importantly, improper removal damages the surrounding shingles, and reinstallation without the correct overlap sequence creates a worse leak than the original problem. We’ve been called to Capitol Hill and Ravenna homes where a well-meaning owner used incompatible sealant or drove fasteners through the flashing pan, turning a $400 repair into a $1,200 fix. If you suspect IKO flashing failure, call (866) 850-9676. A live person answers, we’ll schedule an inspection, and most replacements are done before the next rain moves in.

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