Green roofs are widely recognised as an ideal way of improving air quality in cities. Planners and Councils are beginning to use extensive plantation for air purification in order to reduce carbon dioxide and increase oxygen in the atmosphere. Green roofs also make a significant contribution to reducing polluting air particles and compounds not only through the plants themselves, but also through the growing medium.
They are also increasingly being used in efforts to reduce and delay water run-off during times of heavy and prolonged rain, a fact that can be significant in reducing localised flooding. A recent study in Germany showed that during a 10mm rainstorm, whilst 200 litres of rainwater fell onto an 18m2 green roof, only 15 litres actually passed from the roof to the ground. But given that some water does escape, it’s important to ensure that the waterproofing membrane does not have an adverse effect on the quality of water which is released from a green roof after rainfall.
The waterproofing membrane itself must also be taken into account when thinking about the overall environmental picture. The method of manufacture, component chemicals and long-term environmental impact of the membrane itself can be as significant as the benefits of a bio-diverse ‘green’ roof.
A green roof requires a strong, durable and light membrane to line it. GRP (Glass Reinforced Polyester) is an inert material that can be used with ‘grey’ water harvesting systems and potable water. In service, it does not release any pollutants or chemicals.
Green roofs offer exceptional environmental and cost benefits to other forms of roofing, thus is becoming a mainstream option for commercial and domestic builds.
Dryseal is ideal for use as a waterproofing membrane under a “green” roof installation, for the following key reasons;