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To learn more about the sub-soil drainage system visit and the corporate website:

Located at the roof level of a multi-level car-parking block, the Parking Block Roof Garden is in line with the government’s initiative to further enhance Singapore’s “City in a Garden” image. This roof garden is accessible to the public and is frequently used by residents for recreational activities.

Additional benefits the housing authority wants for a roof top garden:
– Reduce glare
– Reduction in ambient temperature
– Improve air quality
– Barrier to reduce highway traffic noice
– Improved aesthetics

As an intensive green roof, depth of growth media can be as thick as 1m in areas where trees are planted. This roof was designed to withstand the expected extra loading. A root-inpenetrable waterproofing membrane was used. To prevent damage to this membrane, the waterproofing contractor’s scope of work was extended to the installation of the 30mm high VersiCell drainage cell. This drainage cell will not only act as the sub-soil drainage media for the entire roof with its high compressive strength, it also acts as a protective cover for the waterproofing membrane. A layer of geotextile was laid over before commencement of the landscaping works.

The provision of a 30mm high VersiCell drainage layer laid horizontally over the entire roof area allows effective transport of infiltrated rainwater into the rainwater down pipe and at the same time prevents waterlogging of the roof garden.