To provide the Green Roof system to facilitate planting on both regular low-slope reinforced concrete flat roofs and also large expanse of sloped Corus Kalzip profiled metal roofs in the park totalling 35,000 sq m.
Elmich Green Roof was chosen because the wide structural spans of the immense roofs to be greened, one of Asia’s largest, and fast track construction of the park demanded that the system selected must be light and easy to install.
Elmich Green Roof comprises a VersiDrain® 25P water retention and drainage layer, a geotextile filter layer andEnviroMix® GR, a primarily inorganic soil-less lightweight planting media and drought-tolerant plant species that require little or no maintenance.
For the metal roofs, VersiCell® structural drainage/insulation cells were used to fill the space between the metal ridges to create a flat level surface on which a separation sheet and geotextile filter fabric were installed. VersiDrain®25Pdrainage and water retention trays were then installed on top and a filter fabric positioned over the trays enabling 100mm ofEnviroMix® GR to be spread over the trays for the planting of selected drought-tolerant plants.
VersiDrain® 25P facilitates efficient drainage on the green roof. Water and nutrients stored in the cell network of the trays is returned, via capillary action, to the planting media during dry spells, sustaining healthy plants with minimal maintenance. An automated irrigation system was incorporated on the roofs for use during the initial plant establishment and also to deliver regular supply of water and nutrients to the plants.
Waterproofing for the concrete roofs is provided by a fully adhered layer of Evalon PVC/EVA terpolymer membrane, a root-resistant waterproofing membrane, also supplied by Elmich.