A rule based on roof area
The City states it at the top of its LaSalle procedure. Standards vary with the total area of the roof. The procedure does say total area, and it does not explain how to count a roof redone in sections. The permit counter can clarify.
This rule changes nothing for a simple roof repair in LaSalle, which needs no permit. The City places the 300 m² rule under major renovations, where the roofing is replaced.
Flat roofs under 300 m²
For a flat roof under 300 m² in LaSalle, the City requires one of these new materials.
- slate
- clay tile
- wood shingle
- copper sheet
- asphalt shingle
- pre-enamelled roofing sheet metal
- non-corrugated concrete tile
- tar and gravel
- elastomeric membrane
- thermoplastic polyolefin membrane
The City publishes the same list for sloped roofs in LaSalle. Slate and shingles sit right next to the membranes.
For this category, the City page mentions no reflectance threshold and no white colour.
Flat roofs over 300 m²
For a flat roof over 300 m², the City allows the following.
- a material that is white, painted white, or covered with a reflective coating or white gravel
- a material with a solar reflectance index (SRI) of at least 56, confirmed by the manufacturer's specifications or by a professional's opinion
- a combination of these coverings
These requirements do not apply to the part of the roof taken up by mechanical equipment, such as an air conditioner or a heat pump, or by a deck.
Two points remain open on the City page. It does not say what applies to a roof of exactly 300 m². It also does not list a green roof among the options for LaSalle. In both cases, ask the permit counter before choosing the material.
The permit and its fees
According to the borough's page, maintaining or repairing a flat roof in LaSalle requires no permit. A permit is required to replace the roofing, to change the structure, and as soon as the insulation is touched.
The review fees the City publishes are $9.80 per $1,000 of work. The minimum is $167.40 for a strictly residential building and $491.70 for a commercial, industrial, institutional or mixed-use building.
The documents required
For a flat roof in LaSalle, the City asks for:
- the quote or a cost estimate grid, taxes included
- the certificate of location
- the materials technical data sheet, showing the solar reflectance index
- the building record (fiche-bâtiment)
- any other document useful to the review
The technical data sheet comes from the manufacturer. Ask us to attach it to the quote, with the SRI clearly shown.
Do not measure the roof yourself and do not go up on it. Measuring is our job, and the permit counter can tell you how total area is calculated.
Frequently asked questions
Is a white roof mandatory in LaSalle?
No, a white roof is not required on every roof in LaSalle. For flat roofs over 300 m², the City asks for a white material, a reflective coating, white gravel or an SRI of at least 56. Under that area, it gives a list of materials with no reflectance threshold.
What reflectance index does LaSalle require?
For a flat roof over 300 m² in LaSalle, the City asks for a white or reflective material, or an SRI of at least 56. The index must be confirmed by the manufacturer's specifications or by a professional's opinion.
Does a rooftop deck have to be white?
No. According to the City, the requirements do not apply to the part of the roof taken up by a deck or by mechanical equipment.
Official sources, consulted October 3, 2026: