Podium Decks

Podium decks are structures designed to increase usable space, whilst helping manage the conveyance and reuse of rainwater. Used in conjunction with vegetation, they can contribute to creating amenity; rooftop bars and cafés, green areas above car parks and so on. Polypipe surface water run-off source control systems are designed to provide high volume shallow attenuation structures at both roof and podium levels of a building. The systems are designed to capture, treat, store and return surface water run-off to the underground drainage system in accordance with the Environment Agency prescribed site outfall rate – and can attenuate and reuse the rainwater for irrigation, whilst providing an alternative to using potable water.

The Polypipe Source Control system is designed such that there is a level of water held at roof and/or podium during a rainfall event and allowed to discharge from these areas at a known controlled flow rate. The Polypipe system uses its Permavoid 85mm Geocell to provide attenuation which can be increased to 150mm depth if further volume is required. It should be noted that although water is held at roof level, the design limit is always below the maximum geocell height for the critical storm event and, through hydraulic design, there is a maximum time of 24hrs for the system to be fully empty. In practice the time to empty is always significantly below this time limit and the time to half empty is typically 1-5hrs. Therefore, our Source Control systems are designed to remove water from a roof or podium effectively but over a longer time period than a traditional gravity or siphonic rainwater system.