Case Study - National Stone Centre
During this project, we worked closely with the client and a team of ecologists to create a bespoke green roof system which matched local habitats and was in keeping with the remit of the National Stone Centre.
The project took approximately 2 weeks to complete; a foil faced vapor barrier was laid first and bonded to the plywood roof deck. Over this 2 layers of PIR insulation were laid with a total thickness of 165mm. Over this the water proof membrane was laid a single ply EPDM system was used. This was used because it reached the Standards required for use in a green roof system and because the supplier can make up bespoke sheets of the material.
The membrane was laid in only four separate sheets meaning the installation was very quick and efficient. All the joints between the sheets were hot welded and systematically checked for faults.
The waterproof membrane was then cleaned and covered with a protection fleece and over this a drainage board and filter layer were installed. Once this was in place the green roof growing medium was brought up on to site using a crane and spread at depths varying from 100mm to 200mm. The substrate was made from locally sourced soil and stone.
The growing medium was then seeded with species which will thrive in the dry conditions found on a roof. The species in the seed mix include Birds Foot Trefoil, Alpine Strawberry, Wild Thyme, Quaking Oat Grass and Crested Dog’s Tail Grass.
