Do you know what a green roof is? There are basically two models of this type of roof. The intensive one, which is thicker and has a greater capacity to support a larger and more varied quantity of vegetation between 15 cm and 40 cm high. It is much heavier, requiring more careful maintenance.
Besides this, there is the extensive ecological roof model. It is thinner and lighter, with a maximum thickness of 8 cm. The vegetation here is on average 6 cm to 30 cm high. It is much more financially viable, although it does not support much rainwater load.
This type of covering is ideal to bring more sustainability to your project, providing a series of benefits. For this reason, we have separated in this text how the installation of the green roof is done, when you should opt for this type of coverage, and what its advantages are!
How is the installation of a green roof carried out?
Before starting your project, it is very important to prepare your property for the entire green roof installation process. To do this, it is necessary to have drains in your roof to capture the rainwater that will pass through the drainage system.
To count on a good capture, the surface of your slab must have a slope that allows all the drained water to run off. Therefore, the recommended minimum is 1.5%. In addition, it is essential that the roof goes through a waterproofing process.
Waterproof the surface of your slab
There are several ways to accomplish this process, the most common being with asphalt blanket. Therefore, during its application, it is necessary to be very careful with the corners and encounters with drains, preventing the passage of water.
Apply a layer of granular material
Next, a layer of granular material of about 7 to 10 centimeters high is created. It operates as a draining bottom, directly helping to keep your eco-roof airy. Expanded clay is usually used in this process, as it is a lightweight material, relieving the weight on the roof.
Apply a geotextile blanket
The fourth step on how to install a green roof is to apply a geotextile blanket over the previous layer. It serves as a kind of filter, which allows water to pass through to the drainage, preventing the substrate used for the plants from being drained along with the liquid.
Apply a layer of substrate
Soon after this step, a layer of substrate is placed under the roof – it is a soil suitable to receive the vegetation in an ecological roof. This layer is usually 10 centimeters long, allowing the plants to develop with quality. It is also possible to use composted plant soil or black soil during this process.
Install the plants and take care of their maintenance
Finally, the plants chosen for your green roof are installed. Now the last step is the maintenance that this type of roofing requires. You need to take care of it constantly, eliminating any invasive plants that appear over time.
In addition, you need to irrigate your roof in very dry or dry periods. Another important point is the periodic inspection of the drainage system. This way, it is possible to eliminate problems with the structure of your property.
When to opt for a green roof?
Initially, it is highly recommended that you don’t start working on your roof during very humid or windy periods. If you want your green roof to bloom as early as summer, it is necessary to use vegetation mats and to install them before the end of April. This is because after May, flowers and plants are totally dependent on the weather to grow.
Since plants and seeds can take a while to fill your entire green roof, patience is needed to wait for your roof to bloom. Therefore, if the weather is very hot, it is recommended to water your plants at least once a week until the rainy season starts. Be aware, however, that excess water can damage the health of your plants.
What are green roof benefits?
The green roof brings a series of benefits to the residents and to the community around the building that has this type of covering. For this reason, we list its main advantages.
Green roofs are a great choice for those who want to have superior air quality. In addition, plants are responsible for reducing pollution, since they absorb carbon dioxide, releasing oxygen into the atmosphere.
Decreases the heat island effect
Because green roofs do not propagate heat, they end up helping to avoid or decrease the heat island effect – which is a kind of haze caused by contemporary roofing systems. In this way, it is possible to reduce intense heat, bringing more comfort to the region.
Improves the thermal insulation of the property
The use of a green roof is the best way to cool down internal environments. They are capable of absorbing up to 90% more heat than traditional roofs, so that heat is not spread to the rooms in the building. Thus, besides providing more efficient thermal comfort, it is possible to reduce the cost of electricity with the use of air-conditioners and fans.
In hot periods, the green roof can reduce up to 18ºC inside the buildings. In the cold, this is invested by the thermal blanket, facilitating the permanence of warm air inside the house.
Greater retention of rainwater
Vegetation is a great ally during the rainwater drainage process. This reduces the need for a runoff or sewage system. In addition, the green roof is capable of filtering liquid pollution, making it possible to reuse the water for other purposes.
That’s it! Now that you know everything about green roofs, consider the options of this type of coverage to make your property sustainable. Therefore, evaluate well the structure of your house to see if a reform is necessary and use this moment to plan your green roof!