University of Manchester

Bauder Total Green Roof System (BTGRS)


A notable feature on the University of Manchester campus is the Samuel Alexander Building - a five storey Grade II listed building. Erected in 1919 the building has been excellently conserved, however one element that required urgent attention was its flat roof, which had been experiencing considerable water ingress.

Bauder Building Board

Project: University of Manchester
Location: Manchester
Project type: Refurbishment
Roof area: 1,200m²
Specifier: Rider Levett Bucknall
Approved contractor: Briggs Amasco

The specification

The building consists of 12 different roof areas totaling over 1,200m². All of the original waterproofing on the main roof areas was removed before being replaced with Bauder’s reinforced bitumen system, which included PIR insulation. On the building’s lower roof, located in the central courtyard area, 200m² of Bauder’s premium bituminous green roof system was installed along with Bauder plug plants.

Products applied

Bauder Total Green Roof System (BTGRS)
BTRGS provides various environmental benefits including rainwater retention, noise absorption and the creation of new wildlife habitats.

Project challenges

Due to the building’s historical significance it was important that care was taken when installing the waterproofing system. A prime example of this was during the installation of the main roof area where there are coping stones on the roof perimeter that cannot be replaced due to preservation regulations. As a result, the team had to individually lift every stone, lay the waterproofing down and then drop the stone back to its original place. Another project challenge for this project was transporting the green roof products to the roof; consequently the team had to carry all the products through the building at scheduled intervals. All works were completed on time and to budget.

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.


Chris Melling, Project Surveyor at Rider Levett Bucknall:

"Bauder delivered a roofing solution of the highest quality giving us total confidence in the future performance of the roof. The Bauder Total Roof System provides a high-performing bituminous system in terms of both quality and technology.”