We've raised the roof with our new blue-green system

Renovations to the office roof at the Polypipe Building Services site in Aylesford, Kent, provided the perfect opportunity for the pilot installation of the Polypipe Smart Roof 2.1, a new, ‘intelligent’ roof-top system, combining water management with the creation of an amenity for staff, while also increasing the biodiversity of the area with its mix of flora, subsequent fauna – and even a bee-hive.

With water central to the health of a green roof, the ‘blue’ technology aspect of the Polypipe system features on-site ‘firmware’ such as a ‘tipping bucket’ rain gauge to automatically monitor rainfall, alongside remote valve operation technologies, moisture content sensors and self-calibrating heat-flux sensors to measure the rate of heat transfer through the soil. This manages water levels to provide optimum soil moisture, temperature and salinity conditions.

Controlled remotely online, this set-up, known as a Cloud Water Control System, creates the ideal conditions for plant life while maximising water usage efficiency, allowing the roof’s sedum vegetation to flourish and in turn, create valuable habitat – often scarce in an urban environment – for insects and other wildlife.

Indeed, despite the heatwave which was gripping the country at the time of Building Products’ visit to the Polypipe site, leaving many green spaces parched and brown, the roof, which was constructed between March and May, appeared to be thriving.

This is thanks to the incorporation of Polypipe’s unique Permavoid geocellular system. Featuring capillary cones which draw water upwards, stored rainwater irrigates the green roof, while sensors within the cells monitor available water levels. If a predetermined ‘low soil moisture level’ is reached, the system will remotely open a solenoid valve to add water from a rainwater recovery tank, until the correct moisture level is achieved. The system also monitors and controls a back-up water supply to ensure there is always sufficient water available for irrigation. During incidence of high-rainfall, excess water in the wet cell spills over into the raft and feeds into the tank. When the tank reaches capacity, this water overflows to the drain.

The benefit of this advanced technology is a blue-green roof which, according to Polypipe, can be more closely monitored and controlled than ever before, incorporating nature and engineered water management products, in one streamlined system.

A video of the roof is available to view here.