VersiDrain 25P drainage and water retention trays were recently installed on the roof of the HDB car park in Punggol Singapore.

The project was required to provide an extensive green roof on the reinforced concrete roof of the car park to provide thermal insulation and effectively reduce the urban heat island effect.

The VersiDrain 25P drainage and water retention trays were installed over Evalon thermoplastic sheet waterproofing membrane which is both UV and root resistant.

Geotextile was laid over the VersiDrain 25P and EnviroMix GR lightweight inorganic planting media positioned evenly on top. Numerous colourful and drought resistant plants were then planted in attractive patterns.

The green roof systems works by retaining rainwater in the trays during wet periods and distributing this water by capillary action during dry spells, maintaining healthy plant growth.

Green roofs can help to reduce energy costs, improve sound insulation, reduce storm water run-off, and provide a habitat for fauna and flora. Green roofs also help with the reduction of pollution and enable unattractive and heat absorbing roofs and walls to become environmentally sustainable structures.

More information on VersiDrain 25P drainage and water retention trays and their application in green roofs is available from Green Roof Technologies .