Roof Replacement

Most Calgary roof replacements are a tear-off of the old asphalt shingles down to the deck, repairs to any soft or rotted sheathing, new underlayment, eave protection, flashings and vents, and a new layer of shingles. On a typical detached house that is two to four days of work once the weather cooperates, and the season runs from spring to the first hard freeze.

The code sets a floor that a good quote should go past. Under the National Building Code – 2023 Alberta Edition, a shingle roof in a climate as cold as Calgary's needs eave protection running at least 900 mm up the slope and at least 300 mm past the inside face of the exterior wall. The exemption for mild climates does not apply here. The City of Calgary goes further in its own climate advice and suggests a continuous ice-and-water shield over the whole roof when you replace it, because chinook melts and hard refreezes drive water under shingles through the winter.

A like-for-like re-roof on a house in Calgary does not need a building permit. The provincial Permit Regulation exempts re-roofing with a similar material where there is no structural change and no health or safety risk. Changing to a heavier material such as clay tile, changing the roof's structure, or resizing a skylight does need a permit, so ask before you sign if any of that is in the plan.

What moves the price: the number of squares (100 sq ft each), pitch and height, how many layers come off, how much decking needs replacing, the shingle line, and whether you choose an impact-resistant Class 4 shingle. Compare quotes line by line, not by the total.