What the borough allows without a permit
The City's page for Saint-Laurent states that no permit is needed to repair or replace the roofing of a sloped roof.
This rule is more flexible than the flat roof rule. For the City, a roof is sloped from 2:12 up.
Same shape, same load
The borough adds one obligation. You must make sure the roof keeps the same shape and the same load as the existing roof.
The City's page defines neither word and gives no threshold. Shape can be read as the outline of the roof, with its slopes, pitches and dormers.
Load can be read as the weight the roof puts on the building. In practice, ask us two questions:
- does the new roofing weigh about the same as the old one?
- will the old shingles be torn off, or will the new layer go on top?
Laying a new layer over an existing one adds weight. The page does not say whether this practice meets the load condition. Have it confirmed at the permit counter before accepting a quote that plans for it.
When a permit becomes mandatory
Two cases require a permit on a sloped roof in Saint-Laurent:
- changing the structure of the roof
- replacing the roofing with a material other than the one already used
Going from asphalt shingles to sheet metal, for example, is a change of material.
The page does not say whether a shingle of another colour or model counts as another material. If in doubt, ask the permit counter.
Fees and documents, when a permit is required
In Saint-Laurent, the review of the application costs $9.80 per $1,000 of work, according to the City's page. The minimum is $167.40 for a strictly residential building and $491.70 for a commercial, industrial, institutional or mixed-use building. These fees are non-refundable.
The City asks for these documents:
- the quote or a cost estimate grid, taxes included
- the certificate of location
- a data sheet that describes the planned materials and gives their solar reflectance index
- any other document useful for the review
For sloped roofs, the page sets no reflectance threshold in Saint-Laurent. It only asks that the sheet show the index.
Where to go
The service point listed is the Saint-Laurent permit counter, 777, boulevard Marcel-Laurin. For sloped roofs, the page consulted mentions only this in-person option. It refers to the location's listing for accepted payment methods.
Frequently asked questions
Do you need a permit to redo a shingle roof in Saint-Laurent?
No, if you replace the roofing with the same material and the roof keeps the same shape and load. A change of material or structure requires a permit.
Can you switch from asphalt shingles to a metal roof?
Yes, but with a permit, since metal is a different material from the one already used. The load condition also applies. Ask us for the compared weight of the two roofing types.
How can I check my shingles without going up?
Look at the roof from the ground or a window, with binoculars if needed. Curling shingles, granules in the gutters or bare patches are signs worth photographing. We handle the close-up inspection.
Official sources, consulted October 3, 2026: