Edinburgh children’s hospital gets the Polypipe treatment

Polypipe, UK manufacturer of sustainable drainage and water management solutions, has supplied more than 300,000 Permavoid and Polystorm-R components for water attenuation systems at the new £150million Royal Hospital for Children and Young People in Edinburgh.

Polypipe, working with primary contractor Multiplex, has supplied 11 shallow attenuation tanks, that will hold a combined volume of up to 2020m, installed at key points across the site.

Civil engineer and groundwork specialist, Crummock has installed the tanks under parking bays and beneath crucial entrances, including the hospital’s Accident and Emergency departments.

Following discussions with Polypipe’s technical team, the Permavoid geocellular system was chosen by the project Consultant Engineer as the primary engineered solution.

Polypipe says the innate strength of Polypipe geocellular solutions makes them ideal for heavily trafficked areas, and the 95 per cent void fill ratio of the Permavoid system enhances ground attenuation by storing excess water below ground level, mitigating the risk of localised flooding.

The company has also supplied the additional attenuation tank using components from its Polystorm Range, which included Polystorm R, Polystorm Inspect and Polystorm Access.

To make the tanks watertight for attenuation, the Permavoid tanks are being used beneath permeable and non-permeable paving, wrapped in geomembrane.

Permatex, the polypropylene geotextile, has been installed between the Permavoid layers to ensure passive water infiltration into the tanks.

“There were a number of interesting challenges on this project, including the contractor’s need to keep the site open to hospital traffic, and the high water table on site posing a technical problem to solve,” said Rosie Cheetham, Marketing Manager at Polypipe Civils.

“The onsite teams were able to co-ordinate deliveries to meet strict installation schedules, ensuring disruption on-site was kept to a minimum, and the geocellular tanks, positioned above the high water table, provides a high tensile strength and flexibility that will be able to endure all levels of traffic for years to come.”

The Royal Hospital for Children and Young People is set to open later this year.