Bauder Total Green Roof System (BTGRS) with BauderGREEN XF 301 sedum system


This £14 million Waitrose superstore is built on a brownfield site located in Bagshot, Surrey. The new roof features Bauder’s premium root resistant bituminous waterproofing system, BTGRS, which includes a highly efficient 120mm FA-TE insulation to satisfy the required 0.18 U-value.

Bauder Building Board

Project: Waitrose
Location: Bagshot
Roof Area: 4,800m²
Specifier: Forum Architecture
Main Contractor: Midas Group
Roofing Contractor: Span Roofing

The specification

The client wanted the new development to replace the green space lost to the building’s footprint and minimise its overall impact on the surrounding landscape. The Bauder Total Green Roof Systems (BTGRS) provides various environmental benefits including rainwater retention, noise absorption and the creation of new wildlife habitats.

This was achieved through the installation of 4,800m2 of Bauder’s high quality, low maintenance sedum blanket, which is highly visible even at ground level.

Products applied

Bauder Total Green Roof System (BTGRS)
Integrated bituminous roof system incorporating modified root resistant, bitumen membranes and high-performance insulation.

Bauder XF 301 sedum system
A lightweight, all in one system featuring mature sedum on 20mm of extensive substrate and incorporating a multifunctional water retention and filter layer. 


The result

The pre-cultivated sedum blanket was craned into position onto the roof and then laid in a very similar way to turf to produce a continuous sea of green vegetation on the large waved shape roof. Bauder approved contractor Span Roofing installed over 1,000m² of the lightweight sedum blanket each day, providing instant coverage and greening of the building. The blanket features 11 species of sedums with some mosses and grasses to ensure plant diversity.

All roofing works were completed on time and to budget ensuring there was no delay to the store’s official opening, delivering to the client and local community a striking green roof that acts as a visual reminder of the importance of sustainability.

System installed

Bauder Total Green Roof System (BTGRS)

1 BauderPLANT E A torch-applied, root resistant capping sheet. The product features chemically treated bitumen to deliver superior root resistance which has been tested and approved by the FLL. The membrane is reinforced with 250g/m² spunbond polyester fleece to allow the finished product to cope with structural movement without fracture.
2 BauderTEC KSA DUO A self-adhesive bitumen underlayer with “DUO” lap technology to ensure thorough sealing of lap joints, even in lower temperatures. 
3 BauderPIR FA-TE Flatboard insulation used on the lantern roof area to help meet its U-value of 0.15W/m²K. 
4 BauderTEC KSD FBS A self-adhesive SBS elastomeric bitumen air & vapour control layer, with a mica finished upper surface to allow easy bonding of insulation using the specified Bauder insulation adhesive.

Bauder XF 301 sedum system



1 BauderGREEN XF 301 Sedum vegetation blanket instantly providing at least 90% coverage on an extensive green roof. Integrated water retention and filter layer.
2 BauderGREEN AL 40 40mm high perforated edge/drainage trim frames and retains the Bauder XF 301 sedum system.
3 BauderGREEN SDF Multi-functional drainage and filtration layer which prevents the roots of sedum plants from becoming waterlogged.
4 BauderPLANT E Torch-on root-resistant capping sheet green


Jeffrey Thornton of Midas Group stated:
“Bauder delivered high quality, professional support throughout the project, and Span Roofing demonstrated exception levels of workmanship in the installation of the green roof. This eco-friendly building is undeniably a benchmark for sustainable construction and its roof has played an integral part in achieving this.”