Children’s Garden at the Gardens By The Bay, Singapore
To provide an ultra-lightweight green roof system to establish green roof on existing rooftops
VersiDrain® 25P water retention and drainage trays were placed directly over the RC rooftops, ensuring that individual trays overlap by at least one cell row. A geotextile filter fabric was next laid to completely blanket the trays. Geotextile perimeter upturn of about 15cm is glued to the side walls.
EnviroMix PB, a growing media in the form of a lightweight planting board with high water absorbency and retention properties were next installed. Arranged in rows over the geotextile one abutting against the other without the need to affix, the planting board is extremely easy to install. They are also easily cut to fit into or around irregular areas on the roof.
Minimal regular loose media material is required. Only 50mm of appropriate soil mix (depending on plant species selected) was spread over the planting boards for in-situ planting of selected drought-tolerant plants to establish the green roofs on three rooftops at the Children’s Garden. For planting of turf/grass, no additional loose media is required over the planting boards making installation much cleaner. Pearl grass was effectively used to create maintenance paths on the green roofs.
Vital nutrients incorporated into the board during its manufacture help support initial plant establishment whilst its high water absorbency and retention properties help to reduce irrigation frequency. In prolonged dry spells the addition of an appropriate irrigation system helps to maintain and sustain the green roofs.
More than just helping the rooftops to aesthetically blend with the lush greenery of the gardens, the extensive green roofs complement existing solar panels on an adjacent rooftop to support environmental sustainability. By providing an insulation barrier against the elements on the rooftops, the green roofs also offer protection for the waterproofing as well as reduce heat absorption.