Green Roof Soil Depth Lawn

Green roofs with turf are lush usable spaces.

Green roof soil depth lawn.

Planting areas with restricted soil depth or restricted soil volume are notoriously prone to drying out quickly but don t be fooled into thinking you don t need to address drainage. Whether your planting bed is in the lawn green roof or a planter proper drainage is crucial. While installation of a green roof is initially more expensive than a conventional roof a green roof has a much longer life span than a conventional roof. The garden roof lawn assembly is considered a lightweight assembly but with a slightly deeper soil depth and is designed to support sod lawns as well as perennials.

This green roof can be described as a combination of an extensive and intensive roof and therefore is also called a hybrid roof. A variety of plants that grow well in a soil depth of five to seven inches are good to use including certain perennials ornamental grasses herbs shrubs and sedums. Its soil depth is a full 2 inches enough to support many low growing succulents and a limited number of accent plants. Careful plant selection and maintenance is needed to ensure annuals do not become weeds on a green roof.

These require irrigation and a substrate depth of at least 200 mm. It is generally not recommended for hot climates. It is also important to factor in the type and lifetime of the roof membranethat will be used. Vegetables are the other main group of annual plants used on green roofs.

Replacing the impervious surface of a conventional roof with. Or more depending on the depth of the soil. Rooftop lawns are semi intensive green roofs with a total depth of at least 8 inches. The existing roof must be reinforced to carry the additional weight load anywhere from 15 30 lbs sq.

The structural engineer must factor in the weight of completely saturated soil since the plantings and the soil will hold a significant amount of water. Some green roofs are constructed specifically to support sports turf. The lite system is typically used on retrofit projects when the roof is engineered with only 15 to 17 pounds per sf for the green roof component. Unlike conventional earth covered structures garden roof assemblies are lightweight and can be installed on a wide variety of new and existing structures.

Typical engineered soils layered 6 inches deep are 70 percent inorganic materials such as perlite lava rock and vermiculite and 30 percent organic material such as compost. Lawns have unique needs due to the foot traffic they experience. This is especially true of intensive green roofs which can have soil that is two feet deep or more.