A layer of vegetation planted over a waterproofing system installed on top of a flat or slightly sloped roof is known as a green roof. In short, it is a roof that is covered with vegetation. It is known by many other names including:
- Living roof
- Vegetated roof
- Eco-roof
- Rooftop garden
- Sod roofs
The vegetated roofs can be classified according to the type of usage, construction factors, and maintenance requirements. It is classified into three different types; extensive, semi-intensive, and intensive roofs.
Extensive Green Roofs:
This roofing type is also known as eco-roofing. It is a thin, lightweight roof system, and it has a planting media with a depth of between 60-200mm. Extensive GR is usually planted into a layer of shallow soil, and it hosts a sustainable biotic community of herbs, grasses, plants, mosses, succulents, and sedums. Some more details of this roofing are as follows:
- It is one of the cheapest roofing to install.
- It is best suitable for large flat-roof buildings
- Eco roofing is best in those spaces where there is little or no human foot traffic
- It requires low maintenance
- It is suitable for low-sloped residential roofs and retrofits
- It often no need for irrigation and drainage systems
Intensive Green Roofs:
This roofing category offers the widest range of planting opportunities. In this roofing system, shrubs, flowers, and even trees can be used. It has a growing media with a depth of between 150-400mm. It requires deep soil. It is a full landscape rooftop garden with a requirement of regular maintenance. Few more details are:
- Diverse plants and trees can be planted
- The need for an irrigation system
- It has excellent insulation properties
- It can be made very attractive
- It often visually accessible
Semi-intensive Green Roofs:
It is a combination of both extensive and intensive rooftop gardens. It has a thinner planting media than an intensive roof but thicker than the extensive roof with a depth of between 120-250mm. Few more details are:
- It requires a little maintenance
- Planting communities include grass herbs and shrubs
- It requires periodic irrigation when needed
Following these three categories of the green roof has its benefits, and each is ideal for a different location. But all the three have been suggested by many to be a significant breakthrough in resolving global warming. So it is proved that installing rooftop gardens are one of the best ways to protect your environment.