8 Layers of a Sustainable Green Roof
Many people, though they’re interested in the concept, are apprehensive about the sustainability of a green roof. When engineered properly however, a sustainable green roof not only provides incredible indirect benefits to our surroundings, such as improved air quality, but it increases the life cycle of the building itself. A sustainable green roof lasts longer, and provides insulation and weather protection for the building.
To understand the level of engineering that goes into sustainable green roof design, check out its eight standard layers.
1. The roof deck – The actual roof layer itself before the green roof technology is added.
2. A protection board – Acts like a buffer to prevent plant roots from penetrating.
3. A waterproof membrane – On new construction a rubber material like EPDM is used.
4. The insulation – An optional layer which depends on the climate. Insulation prevents the vegetation from extracting the building’s heat during the winter or cold air during the summer.
5. Drainage & storage – Acts as another root barrier and prevents root rot as well as manages water retention.
6. Protective fabric – A tough synthetic layer of fabric that protects the waterproofing material and may also act as a filter in some circumstances when it has a capillary design.
7. Grow medium – Typically a light weight engineered soil, expanded clay pebble, perlite, or volcanic rock. The grow medium must be water retentive to ensure healthy plant growth but not become heavy when wet.
8. The plants – Vegetation is chosen specifically for the particular climate and amount of sun exposure. Plants can also be chosen depending on the desired depth of the green roof’s design.