Alder Hey - HousebuilderLeading flat roof waterproofing system provider Radmat Building Products has supplied an award-winning roofing system for the new £237 million Alder Hey in the Park children’s hospital in Liverpool. The system provides high standards of environmental performance, long term waterproofing integrity and has enabled the creation of three stunning green roofed ‘fingers’ that connect the hospital with the surrounding parkland.

It was important to select a waterproofing system suitable for the green roof. Radmat Building Products selected a two coat Liquid Applied Membrane chosen for its speed of installation and elastomeric properties allowing it to expand and contract with the building. The ease of application also meant a safer process for those working on the less accessible areas of the roof.

Alder Hey is the first hospital in Europe to be built entirely within a park. The 52,600m2 main hospital and 9,500m2 outpatients department was designed by architects BDP in consultation with patients, their families, the Princes Foundation and National Arts for Health, and was inspired by a drawing made by a 15-year-old patient. The 270-bed hospital is one of the most sustainable ever built, with more than 50% of its energy generated on site.

Laing O’Rourke appointed Radmat approved contractor, Prater, to construct the green roof on the strength of its technical expertise and previous experience on major healthcare projects and green roof systems. A key feature of the hospital’s design is the three iconic green roofed ‘fingers’ that curve downward from the fourth floor of the building to the ground level at a 45-degree angle, connecting the hospital wards with the surrounding parkland.

The structure posed installation challenges and in order to safely waterproof the steep slopes the installation team to work using a mixture of abseiling equipment and telelifters to apply two coats of a Liquid Applied Membrane, which was developed for use in verdant roof gardens. The liquid applied system was chosen for speed of installation and its elastomeric properties, allowing it to expand and contract with the building to ensure a reliable seal. The ease of application also meant a safer process for those working on the less accessible areas of the roof. This was followed by installing Radmat’s ProTherm Inverted Roof Insulation, specifically designed to give effective, long-lasting insulation on inverted roofs. The green roof was completed with a substrate-based Wildflower Meadow System.

The main hospital and outpatient’s department have already won a number of RIBA Awards and can now add a Roofing Award to the many accolades it is no doubt going to receive. Radmat and Prater were awarded the ‘Green Roof Project of the Year 2016’ in the Sustainability category of the UK Roofing Awards for their work on the hospital, which is a home-from-home for children who need care, and gives them access to play areas, fresh air, natural light and striking views of the park.