What Wind Damage Looks Like on a Roof, and Why Creased Shingles Matter

Greater Victoria's wind comes mostly from the southeast in winter storms and the region's exposed edges take it first: the Dallas Road and James Bay waterfront, the Cordova Bay bluffs facing Haro Strait, Sidney and North Saanich shorelines, the Royal Bay and Esquimalt harbour fronts, and the ridges of Bear Mountain where elevation adds gusts. Inland Saanich streets a kilometre from the water often see no damage from the same storm, which is why wind damage is so site-specific here.

The house type matters too. The steep, cut-up Tudor and Arts-and-Crafts roofs of Oak Bay have many rakes and hips, each an edge for the wind to grab, while the simple gables of 1970s Sidney ranchers lose ridge caps and little else. On the 2000s subdivisions of Langford and Colwood, ridge-cap loss on builder-grade shingles a few years in is common enough that a roofer will check the cap nailing and sealant before blaming the wind alone.

Wind does not push a roof down; it pulls it up. Air accelerating over the ridge and around the corners of the house creates suction, and it is strongest at the ridge, along the rakes (the sloped edges at the gable ends) and at the eaves and corners. That is why a windstorm strips ridge caps and edge shingles and leaves the middle of the slope alone. Shingles resist by sealing to each other with a heat-activated adhesive strip and by their nails, so anything that weakens either, such as age, a cold-weather install or high nailing, shows up at the edges first.

The costly wind damage is the creased tab. In a gust the shingle lifts, folds back on itself, then lies down again when the wind drops. From the driveway it looks fine. Up close the fold has cracked the fibreglass mat and the granules along the crease are gone, and the seal is broken, so the tab lifts more easily next time and water can enter at the crease. A roofer checks for creasing by gently lifting tabs on the windward slope by hand, which is not something to do from a ladder.

Creasing also tells you something about the roof's age. Young, flexible shingles fold and recover; brittle ones crack outright. A slope where many tabs are creased after one storm is often a slope near the end of its life.

The window between storms in a Victoria winter can be days. Use it to:

• Photograph every slope from the ground, especially the ridge and rakes, and keep any caps or shingles you find.
• Check the attic and ceilings for new water after the storm and again after the next rain.
• Book a roofer to hand-check the windward slope for creases and lifted seals, not just the obvious gaps.
• Ask for a temporary cover ($300 to $800 in our pricing model) if shingles are missing and rain is due.
• Clear gutters of storm debris so overflow does not add a second problem at the eaves.

On a roof under 15 years, wind damage is normally a repair: creased and missing shingles are replaced, ridge caps re-nailed with new caps, edges resealed. On an older roof the decision turns on brittleness and extent. If lifting a tab to slide a new one under cracks the old one, or if several slopes are affected, a roofer may recommend a cover for the season and replacement in the dry months. Insurance can help with sudden wind damage but a BC claims guide notes older roofs may be settled at depreciated value, so get the repair estimate before assuming a claim is worthwhile.