Should skylights be replaced when my Calgary roof is replaced?

Skylights don't have to be replaced at the same time as your roof, but it's often the smartest moment to do it, and the decision hinges on the skylight's age, condition and how it's flashed into the new roofing.

Should You Replace the Skylight Now?

A roofing crew will remove and reinstall the flashing around every skylight on the roof regardless. That labour is already priced into the job. If the skylight itself is more than 15 to 20 years old, the seals between the panes are likely failing or close to it, and the frame may be warped or cracked from Calgary's roughly 128 freeze-thaw cycles a year. Replacing the unit now costs far less than pulling up new shingles in two or three years to swap it out then, because you'd be paying for a second round of flashing work and a patch on a brand-new roof.

If the skylight is relatively new, the glazing is clear and the frame is solid, a good roofer can reflash it properly into the new roof and leave it in place. Ask the roofer to inspect the frame, the curb (the raised frame it sits on) and the existing flashing during the quote visit, not after they've started tearing off.

Flashing is the critical detail. Most skylight leaks in Calgary aren't caused by the skylight itself; they're caused by failed step flashing, a cracked curb or ice damming that forces water under the flashing in winter. When new shingles go on, the roofer should install new step and counter-flashing around the skylight, and the ice-and-water shield should run up and around the curb. The National Building Code (2023 Alberta Edition) requires eave protection extending at least 900 mm up the slope and to a line at least 300 mm inside the inner face of the exterior wall on Calgary roofs; that same self-sealing membrane should wrap the skylight curb as well.

On the permit question: the City of Calgary's guidance says replacing or repairing roofing materials doesn't need a permit. Replacing a skylight with one of the same size also doesn't need a permit. Installing a larger or smaller skylight does require both a development permit and a building permit from the City of Calgary, so if you're thinking about upsizing, sort that out before the roofers arrive.

Costs to factor in: a standard skylight replacement, including the unit and new flashing, typically runs $800 to $2,500 depending on size and type, and that price drops meaningfully when it's bundled into a full re-roof because the crew is already set up on the roof. A fresh flashing-only job on an existing skylight might run $300 to $700 on its own.

A few things worth asking any roofer who quotes this job: Will you inspect the curb and frame before deciding whether to reflash or replace? What brand and type of flashing kit are you using? Is the skylight replacement itemised separately so I can see exactly what I'm paying for it? And will the new installation include ice-and-water shield around the curb?

If your roof is also hail-damaged and you're going through insurance, mention the skylight to your adjuster. Hail can crack or pit skylight glazing, and if it's damaged it may be part of the claim scope.

Ask every roofer who quotes your re-roof to price the skylights both ways, reused and replaced.