New build bungalow with low pitched sedum roof in Woodingdean, UK

Woodingdean is a rural town situated amongst the Downs near the south coast. The project involved the construction of a bungalow on land that had once belonged to an adjacent property. This is overlooked by the surrounding housing, and so a sedum roof was chosen as a functional solution that blended in well with the surrounding area.

Construction and Materials

The bungalow was constructed to include a wooden deck as the underlying roof structure, and then the sedum roof build-up applied. A 20 mm studded drainage membrane was specified as the drainage solution for the roof, which acts as drainage detail with reservoir capability. This also provides an additional layer of protection for the waterproofing membrane, helping to prevent deterioration and prolonging the life of the green roof. A geotextile fleece is laid upon the drainage membrane which acts as a filter for water travelling through the sedum and soil layer, helping to purify rainwater by retaining the larger polluting molecules.

Application

Firstly exterior grade roofing felt was installed on top of the wooden deck. Then the drainage solution was laid on top of the felt, followed by a geotextile filter fleece. 25 mm of specially mixed roof soil is then raked on top of the fleece, with a sedum blanket set down as the final layer.

The roof was supplied and installed by a collaboration of Mitie Roofing, Safeguard and Paul Slawson of Evergreen Roof Gardens.

The Result

The client was very impressed with the end result, and the owners of overlooking property felt it appeared as “an extension of the garden”. The roof itself was put together easily and quickly, and a few months later can be seen to be flourishing. It has already helped reduce excess rainwater runoff and hence reduced the load on local drainage systems.

The roof acts as a waterproofing system and provides good insulation throughout the year, helping to keep the building cool in summer and warm in winter. The inclusion of the green roof in this new development has been a point of interest and not concern for the neighbours in this rural location.