What’s a Green Roof in Los Angeles Made of?

A green roof in Los Angeles serves as a perfect insulating system in this city where the sun shines generously all year round. A green roof not only makes a home or any building look attractive, it effectively cools a building and it helps residents save on energy costs.

But just what is a green roof made of that makes it a perfect spot for growing grass and other types of plants?

To create a green roof that won’t destroy parts of the building due to water leakage, a waterproof membrane is laid over the roof.

Adding a root barrier prevents roots from working their way through the protective water membrane and into the roof. Concrete and cellular glass are usually the materials more commonly utilized as a root barrier.

Next to the root barrier is the drainage layer. When properly installed, the drainage layer efficiently carries away water to the drainage gutters; avoiding water from getting trapped elsewhere in the roof and from causing damages to other parts of the building.

Placing a filter fabric holds the soil in place, preventing it from eroding and from scattering all over the building. The filter fabric should be porous enough to enable water to flow freely down in to the drainage area without eroding the soil. The most common types of materials used as filter fabric are polypropylene and polyester.

Soil for the plants to grow on could be derived from local soil. However, to prevent the introduction of weeds that could destroy your plants, it’s recommended for a green roof in Los Angeles to use crushed clay or sand mixed with humus to provide nutrients to the growing plants. To make it easier for the plants to grow, it is recommended that the soil should have a depth of at least three inches.

Other components of an efficient green roof include drip irrigation to evenly distribute water to areas of the roof where it is needed the most, preventing uneven roof pressure caused by uneven water application when plants are being watered using a conventional hose.