Green Roof Growing Medium Thickness

A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium planted over a waterproofing membrane it may also include additional layers such as a root barrier and drainage and irrigation systems.

Green roof growing medium thickness.

All three types of roofs require specific layers of roofing materials not found on regular roofs. Extensive green roofs substrate based green roofs. These aggregates make a good basis for a growing medium. The substrate sits on the green roof system filter sheet drainage layer protection layer.

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. 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. In short a green roof is made to purposely grow grass. These materials are available throughout the west coast of north america.

To make this process work various green roof layers are created to give it the most effective and solid chance of being successful. Pumice is somewhat porous and is lighter than most aggregates. The layers of a green roof are as follows from top to bottom. Green roofs are differentiated by the depth of the growing medium as this directly relates to weight the primary structural concern.

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. The substrate is usually an aggregate mixed with about 20 organic material. Container gardens on roofs where plants are maintained in pots are not generally considered to be true green roofs although. These extensive green roofs generally have 80mm of substrate.

Lightweight volcanic aggregate such as pumice or lava.