Roof maintenance in Victoria: a spring and fall checklist

Roof maintenance advice written for the rest of Canada is about ice dams and snow load. Here it is about water that never quite leaves. The Roofing Contractors Association of BC describes the coast and Vancouver Island as temperate rainforest, and says roof areas shaded by overhanging trees or other buildings stay cool and damp for longer, which is what moss needs. BC Housing adds that a build-up of moss holds moisture on the roof and can lead to premature failure of shingles on a sloped roof.

So the local version of maintenance is mostly three things: keep debris off, keep gutters running, and keep moss from getting established. A roof in full sun in Langford and a roof under Douglas fir in the Highlands are on different schedules, and the second one is the one that needs attention every season.

The National Roofing Contractors Association says a homeowner's own maintenance should be confined to inspecting the roof in fall and spring for cracked or curling shingles and cleaning gutters, and to staying on the ladder and off the roof. CMHC's maintenance schedule says to check the general condition of the roof from the ground. BC Housing says the inspection itself should be done by a professional roofing inspector or contractor, because it involves specialised knowledge, equipment and safety requirements.

That gives a sensible division. You watch the roof, keep the gutters clear if the house is low enough to do it safely, and notice change. A roofer goes up, re-secures flashing, replaces damaged shingles and reseals what has failed.

The association's consumer guide is specific. Roofing manufacturers and associations recommend against power washing, which can erode the granules that protect asphalt shingles. Existing moss can be removed with a broom or a plastic scraper. It is nearly impossible to remove every root, so moss comes back, and treatment is part of the job rather than an extra. Zinc or copper strips near the ridge are usually effective for ten to fifteen feet down the slope, and zinc sulphate products can work for a year or more.

It also says that hiring a service is the easiest and safest approach, and to keep overspray off plants and out of ponds and drainage. In our pricing model moss removal with treatment is $400 to $1,200 before GST for a typical house.

Not in the middle of a slope. The association's guide says flashings and other roof penetrations are the source of most leaks, and a shingle manufacturer's maintenance guide lists cracked and worn rubber boots around vent pipes among the first things to check. It also warns against letting a downspout from an upper roof discharge directly onto the shingles of a lower one, which is a common detail on two-storey houses with a porch or garage roof.

This is why a maintenance visit is worth having even on a roof that looks fine from the street. The parts that fail first are the small ones you cannot see from the ground.

Less is written down than people assume. Of the shingle warranties we read, only one lists failure to perform required roof maintenance as an exclusion. The others do not set a maintenance schedule, but they exclude damage from things maintenance prevents: debris and drippings from trees, moss, and foot traffic. So a neglected roof can fall outside a warranty without any clause saying maintenance was required.

A RoofStar guarantee from an RCABC member is different: it does require the owner to maintain the roof, and repairs during the guarantee must be done to its standards by a member. The association's own guide puts it bluntly: do not expect a guarantee to keep the water out of your building. BC Housing recommends keeping a record of what was done and when, which is also what a buyer's inspector will ask for.

BC Housing, the BC roofing association and the US roofing association all say twice a year. One shingle manufacturer says at least once a year by a professional. A national guide that sells contractor leads says a professional inspection every few years. None of them is wrong for every roof. A young roof in full sun can be watched from the ground; from about 15 years on, or under trees at any age, a yearly look by a roofer is the better habit.