By William Kooncea and Mark Anaterb, Dow Chemical Co.
Green roofs are becoming increasingly popular in urban areas. At the simplest, a green roof is usually a flat or slightly inclined roof on which plants are grown in a thin layer of soil.
As well as the basic roof function — shielding the building from cold and heat, rain and snow — green roofs have additional benefits. These include conservation of energy, extension of the service life of the roof, reduction in storm water run-off and flow rates, an overall cost reduction over the life of the roof and a restoration of ecological and aesthetic value to open spaces in urban areas.
To capture all these benefits, it is vital that green roof systems have a high-performance waterproofing membrane which protects the underlying substrate from ingress of water and any subsequent short- and long-term damage.
Among the materials being used, the Verdiseal polyurethane-based monolithic membrane offers a high level of performance. It is easy and fast to apply and has good performance characteristics, such as dimensional stability over a wide temperature range, low-temperature flexibility, seamless sealing, crack-bridging ability, rupture resistance, and low VOC (volatile organic compound) and low noxious odour installation.
Green roofs, also referred to as eco-roofs, landscaped roofs, living roofs or roof gardens, are defined as either partially or completely vegetated. The concept…