How much do zinc or copper strips cost installed?

Strips are a Saanich and Highlands product more than a Sidney one. The roofs that justify them sit under Douglas fir and cedar, face north, or back onto Mount Douglas, Mount Tolmie or the Cedar Hill golf course, where moss returns within a year of treatment. A sunny south-facing Fairfield roof or a wind-scoured Dallas Road roof may never need them. Because a strip only treats the 15 feet below it, the long single slopes of a 1960s Gordon Head or Broadmead rancher are ideal, while a cut-up heritage roof in Rockland with short hips and dormers needs several runs and gets less value from each.

Copper is common on the higher-end roofs of Oak Bay and the Uplands, partly for its longer active life and partly because it weathers to match the copper gutters those houses often carry. That pairing is fine; what does not pair is a zinc-sulfate powder treatment on a roof with copper gutters or flashing, which the University of Washington horticulture library warns can corrode the copper. Ask what metal your gutters are before choosing the strip or the treatment.

A roll of zinc strip is a modest hardware-store item; the installed price reflects a crew setting up fall protection (required by WorkSafeBC once the eave is 3 m off the ground), lifting the ridge cap, sliding the strip under, fastening and sealing it, and doing that on both sides of every ridge. On a 7/12 or steeper roof the crew needs personal fall protection, which is why a steep heritage roof costs more to strip than a bungalow. Never install strips yourself from the roof surface; if you want a DIY route, the only safe version is on a low single-storey roof reachable without walking it, and even then most people hire it out.

No. Extension guidance from Oregon State and the University of Washington is consistent: remove the moss first, then the strip slows regrowth in the zone rain washes across. Strips do not kill established moss, do not work where rain does not flow over them (under dormers, on the far side of a valley), and are less effective on the lower reaches of a long slope. Expect the treatment interval to stretch, not to vanish. A 2026 Victoria guide still recommends treating every 12 to 18 months on high-risk roofs even with strips.

• Remove existing moss before installing
• One run per 15 ft of slope below the ridge
• Place a run under dormer ridges and above valleys
• Re-check the strip when the ridge cap is replaced

Skip them if the roof is within a few years of replacement; put the money toward the new roof and have strips or a moss-resistant shingle built in then. Skip them on a metal roof, which does not need them. And skip zinc sulfate powder anywhere near copper gutters or a fish pond, choosing a strip or a professional non-corrosive treatment instead.