Green Roof Growing Medium Thickness

The vegetation layer consists of sedums and wildflowers.

Green roof growing medium thickness.

The substrate is usually an aggregate mixed with about 20 organic material. The soil is usually not more than 5 deep and is sometimes contained by a tray system which provides a barrier to excessive growth protects the roof membrane and also interlocks the. Container gardens on roofs where plants are maintained in pots are not generally considered to be true green roofs although. These aggregates make a good basis for a growing medium.

To make this process work various green roof layers are created to give it the most effective and solid chance of being successful. The layers of a green roof are as follows from top to bottom. The basic anatomy of a green roof consists of vegetation growing medium filter membrane drainage layer waterproof root repellant layer roofing membrane support for plantings above thermal insulation vapor control layer and structural roof support. These materials are available throughout the west coast of north america.

These extensive green roofs generally have 80mm of substrate. In short a green roof is made to purposely grow grass. Green roofs are differentiated by the depth of the growing medium as this directly relates to weight the primary structural concern. The substrate sits on the green roof system filter sheet drainage layer protection layer.

Pumice is somewhat porous and is lighter than most aggregates. Intensive roofs are those greater than 4 inches in thickness with some as deep as 2 feet or more making a wide variety of plants including bushes and even small trees possible. Extensive green roofs are generally made up of a very thin layer of soil or other planting medium with shallow root plants like sedum mosses and grasses. For the best green roof medium the growing media should contain the following.

Lightweight volcanic aggregate such as pumice or lava.