Optigrun and Bridgman & Bridgman have combined to produce a stunning 47º pitched green roof for a private residence in the coastal village of Salthouse, North Norfolk.
The teams at Optigrun and Bridgman & Bridgman have worked together to deliver a green roof with an extremely steep 47º pitch.
The private residence, located at Salthouse near Cromer, North Norfolk, was originally designed by the owner with a roof slope of 52.5°.
The project presented a number of challenges including most notably the steep pitched sedum roof requirement and the need to prevent slippage of the substrate and vegetation mat; dealing with drainage run off at the base of the slope; and the North Norfolk sea front location and weather conditions presenting concerns around issues such as wind uplift.
Optigrun provided detailed technical assistance to find a green roof solution that would work on such a steep pitch, with the design being adjusted to a pitch of 47°.
The solution incorporated a structured storage fleece SSV800 between waterproofing layer and substrate to store water and provide drainage, and Type N anti-slip system comprising base netting and sills.
The SSV800 layer was laid across the entire roof followed by the Type N netting. Because the length of slope was the same on both sides of the roof, the net was laid from eaves to eaves without needing to be fixed.
The anti-slip sills were then clipped to the netting in a staggered pattern. The anti-slip system was then covered with extensive substrate and a pre-cultivated sedum vegetation mat. An Optigrun TSK channel system was laid at the base of both roof slopes to accept and direct excess water to the roof outlets. At the outlets, the channel was connected to an Optigrun inspection chamber.
The 47º pitch is said to be pretty much as steep as a green roof can go before it becomes a green wall, and despite its coastal location, the roof is said to have already stood up to a record 67mph storm from the North Sea.