DETENTION GREEN ROOF
Urbanscape® Detention Green Roof − an innovative, easy to install green roof design with a key purpose to maximize water retention and at the same time optimize water detention during peak storms.
Urbanscape® Detention Green Roof − an innovative, easy to install green roof design with a key purpose to maximize water retention and at the same time optimize water detention during peak storms.
Urbanscape® Detention Green Roof − an innovative, easy to install green roof design with a key purpose to maximize water retention and at the same time optimize water detention during peak storms.
The Urbanscape® Detention Green Roof has been evaluated and tested by Green Roof Diagnostics.
It pioneers detention for an effective green roof stormwater management. It is the optimal solution for short, intense storms with limited rainwater volumes. It delays runoff and reduces peak runoff intensity in order to comply with stormwater detention requirements for design storms.
Green roofs typically provide stormwater retention, as they capture water (preventing water from draining) and then allow the water to evaporate only through evapotranspiraton processes. However, retention is not always effective as it fills up the entire empty storage space in green roofs and then takes time to dry out and make room for new rainwater. On the contrary, the Urbanscape® Detention Green Roof first captures (and retains) the water and at the same time slows down the water flow, still allowing it to drain. The additional detention layer used in Urbanscape® Detention Green Roofs significantly increases friction and slows down the water runoff, which means it is always ready for the next storm.
It is crucial to understand that excessive urbanisation has destroyed the natural cycle of water (precipitation – infiltration − evaporation) as there are simply too much paved surfaces in dense urban areas which prevent proper infiltration of rain water into the ground. With the Urbanscape® Detention Green Roof the water cycle can be restored.
The Urbanscape Detention Green Roof System is pioneering detention in green roofs. It delays runoff and reduces peak runoff intensity in order to comply with stormwater detention requirements which reduces the burden on sewer systems and consequently causes cost reduction due to no or low need for rain harvesting cisterns and similar equipment, usually used for storm water management. The detention feature of the Urbanscape Detention Green Roof helps to limit accidents caused by heavy rainfalls.
The Urbanscape Detention Green Roof retains more water than any other vertical assembly. It provides fast and long-term stable water re-absorption and retention performance and helps to rebuild a healthy water-cycle.
Green roofs should not be one-size-fits-all. The Urbanscape Detention Green Roof is designed for and adjusted to different environments and climates.
Through natural biofiltration, green roofs prevent contaminants and toxins from reaching streams and waterways. According to Kohler & Schmidt research (1990) 95 % of lead, copper and cadmium sulphides, and 19 % of zinc coming from the rainwater remain in the substrate which helps to improve the local water quality.
The Urbanscape® Detention Green Roof System ensures a long-lasting cooling effect due to the high water-storage capacity. Compared to the non-vegetated roofs, roofs with the Urbanscape® Green Roof System reduce heat gain due to the thermal mass, extra insulation, and evapotranspiration associated with vegetative roofing systems.
The Urbanscape® Detention Green Roof system can be installed also on lightweight constructions where the installation of traditional systems is not possible. Further on, the Urbanscape® Detention Green Roof System can also be much thinner (decreasing the weight even more) than traditional green roof system. A lesser thickness of the system will not compromise the performance, therefore the same water absorption and detention are achieved with a lesser thickness of full assembly .
The Urbanscape® Detention Green Roof System is provided with complete, easy to install layers delivered directly to the customer.
The Urbanscape® Detention Green Roof is a complete system which consists of a detention layer, storage layer, a growing media – a unique patented rock mineral wool – and a vegetation layer. It has been evaluated and tested by Green Roof Diagnostics.
The Urbanscape® Detention Layer T5 is a three-dimensional, lightweight and flexible drainage sheet that functions as a retarding element for draining water in a delayed manner through friction. The sheet is made entirely of nylon. Both, the top and bottom of the sheet are tightly woven and function as a root-resistant and filtering layer. In between there is a machine-woven pattern of vertical threads that cause friction which creates the delay in draining water.
The Urbanscape® Storage Layer HC40 has the function of detaining water. It reduces the flow rates of the Urbanscape® Detention Green Roof assembly. It is a panel of small diameter, with solid-wall tubes, vertically oriented, and fused as a panel. This honeycomb structure consist almost entirely of macropore space (>90% void space) with negligible horizontal water flow.
The Urbanscape® Green Roll is a lightweight, multi-functional green roof growing media, made of long rock mineral wool fibres specially needled to form a compact and dimensionally stable felt. The product is made completely of virgin rock mineral fibres. It ensures excellent water retention and conservation in green roofs (acts as a sponge) and is a good growing medium made from various mineral mixtures.
The Sempergreen Sedum-Mix blanket is the top layer in the Urbanscape® Detention Green Roof structure and has the function of evapotranspiration (a combination of evaporation and transpiration). The sebaceous Sedum plants are capable at storing water in their leaves and have a high adaptability so that they can survive under various (extreme) weather conditions. In case of extreme precipitation, the surplus water evaporates through evapotranspiration.