Roofing in Duncan

In the Municipality of North Cowichan, re-roofing and replacing exterior cladding are listed as exempt from a building permit unless structural repairs are required or insulation is being replaced or upgraded. The City of Duncan and the CVRD electoral areas set their own requirements, and the City directs homeowners to its Development Services building inspector to confirm. Anything that changes the structure, adds new sheathing, or forms part of an addition should be treated as permit work until the local building department says otherwise.

A full asphalt shingle re-roof on a typical Cowichan Valley home generally falls between $8,000 and $20,000, which works out to roughly $4 to $9 per square foot installed. Metal systems run higher — commonly $18,000 to $45,000 or more depending on profile and complexity. Targeted repairs usually land between $500 and $3,000. Roof size, pitch, number of existing layers, deck condition and access all move the figure, so an on-site assessment is what produces a real number.

Asphalt shingles are rated for roughly 15 to 30 years, and metal systems for 40 to 70. On the coast the low end of that asphalt range is common, because sustained rain, shade and moss shorten service life well before the shingle itself wears out. Roofs that get moss treated and gutters cleared on a regular interval reliably outlast roofs that do not.

Duncan takes in about 1,500 mm of precipitation a year against roughly 705 mm in Victoria and 1,165 mm in Nanaimo, and most of it falls between November and January. Combine that with tree cover from Douglas fir and cedar and shaded north-facing slopes, and roofs stay damp long enough for moss to establish. Moss holds water against the shingle mat and lifts the edges, which is what turns a cosmetic problem into a leak.

Metal sheds water fast, does not host moss the way an asphalt mat does, and carries a 40 to 70 year service life against 15 to 30 for shingles. The trade-off is upfront cost — typically two to three times an asphalt re-roof — plus detailing at penetrations and valleys that has to be right. Metal makes the most sense on roofs that are exposed, steep, heavily treed, or awkward to access for maintenance.

British Columbia does not issue a provincial roofing trade licence, so 'licensed roofer' means very little on its own. What can actually be verified is WorkSafeBC coverage, commercial general liability insurance, and manufacturer certification for the specific system being installed. Asking for all three in writing before work starts is reasonable and standard.