The installation of vegetated roofs, or green roofs, is increasingly popular among Quebec homeowners. These ecological roofs offer numerous benefits. There are two types of green roofs: the intensive green roof, often associated with a garden or vegetable patch, and the extensive green roof, without cultivation. The intensive roof requires rigorous maintenance but quickly becomes an integral part of homeowners' lifestyles. These roofs are particularly appreciated in the Montreal region, where they are often installed on flat roofs, although sloped roofs can also accommodate them.

A green roof is composed of several essential layers. The first is a membrane, generally made of elastomer or plastic, which ensures perfect waterproofing against the elements. Next, a water retention layer allows vegetation to nourish itself without requiring constant drainage. A geotextile membrane ensures roof filtration, and a layer of soil or fertilizer is added to allow vegetation to grow. This configuration allows for optimal water management and effective protection against Montreal's harsh climatic conditions.

Green roofs offer multiple benefits for the city of Montreal and its inhabitants. They help reduce heat islands, especially during heatwaves, which improves the quality of life. Furthermore, they provide an excellent means of thermal insulation, reducing buildings' energy consumption. In summer, the absorption and transformation of solar energy by vegetation help keep buildings cooler.

Advantage #1 – Aesthetics:
Green roofs bring a rare touch of greenery to the city. They enhance the appearance of any building, particularly in cities like Montreal, Laval, or on the South Shore.
Advantage #2 – Insulation:
Vegetated roofs provide additional insulation against temperature fluctuations. In summer, they help reduce the internal heat of buildings.
Advantage #3 – Vegetation:
A well-maintained green roof can be transformed into a vegetable garden, allowing for the cultivation of fruits, vegetables, and herbs. This can be a source of self-sufficiency for homeowners.
Advantage #4 – Long Lifespan:
Green roofs, when well-maintained, can last up to 30 years, thus offering an excellent long-term return on investment.

One of the main disadvantages of vegetated roofs is their weight. Before installing a green roof, it is crucial to verify that the roof structure can support it. A professional can recommend modifications if necessary. Furthermore, the installation of a green roof can be costly, which may deter some homeowners. Maintenance is also essential, especially for roofs with gardens, which require regular watering and monitoring to prevent major repairs. Annual maintenance, sometimes required by insurers, is essential to ensure the longevity of the green roof and prevent potential problems.