University of West England W Block

BauderThermofol PVC single ply waterproofing system with profiled infill overlay system


The University of West England is a higher education provider, located in Bristol. W Block, situated in the main Frenchay campus had become dated, therefore the building undertook a full refurbishment to transition into a modern faculty centre for fine print research. 

The existing single ply waterproofing and composite panels were aged and failing, therefore the specifier’s main objectives with this refurbishment project, were to source a lightweight waterproofing solution and thermally upgrade the roof.

This project was shortlisted by the Single Ply Roofing Association (SPRA) for Best Refurbishment 2021 and Best Sustainability 2021. 

Bauder Building Board

Project name:

University of West England – W Block



Project type:


Roof size:



John Perkins Construction

Approved contractor:

Urban Roof

The specification

Bauder Thermofol single ply system was chosen to overlay the existing single ply and pitched composite panels due to its lightweight properties and versatility. This membrane can successfully join the existing single ply and metal composite panels together to form one continuous roof covering inclusive of a thermal upgrade.

Project challenges 

One of the main challenges during this refurbishment project was the weather, as the work was being carried out mid-winter.  Roofing adhesives should be stored in temperatures between 5-25˚c . When adhesives are cold, their viscosity can increase making the product thicker and more difficult to apply. Initially an adhesive membrane attachment was specified, but to overcome the challenge caused by cold temperatures, the method of membrane attachment was changed to mechanically fastened.

The result

During the installation, the existing composite panels were overlaid with trough infills to create a flat surface where insulation was mechanically fastened above. The existing single ply areas were overlaid with solely the Bauder FA insulation. Bauder Thermofol membrane was then mechanically fastened over the entire area. Decorative profiles to replicate standing seams were then installed to the pitched area.

Our infill overlay system is primarily intended for refurbishing profiled sheet metal roofs or increasing the thermal performance of existing insulated cladding systems. This system provides a high compressive strength, simplicity of installation and excellent thermal performance.

At the specification stage, U-value calculations were carried out to determine the minimum thickness of insulation needed to ensure that the roof satisfies the current building regulations. This calculation also identified that the existing coverings could be re-used as the air & vapour control layer. By doing this, the client benefitted from cost savings resulting from the reduction in substantial amounts of labour and materials. Not only was the roof thermally upgraded, but the completed project was aesthetically pleasing. On completion, a full system product & workmanship guarantee was issued for the new roof.

The client benefitted from:

  • This system achieving fire classification BROOF (t4) and verified by the BBA as ‘unrestricted’ and suitable for use on any part of a roof.
  • The insulation infill solution being suitable for use with Thermofol (PVC) and Thermoplan FPO systems,
  • BBA certified product,
  • Single source supply,
  • ​One point guarantee,
  • No building interruption,
  • More cost effective than recladding.

System installed

Bauder Profiled PIR Infill Overlay System

1 BauderTHERMOFOL U 15 V FR  3.5mm fleeced-backed waterproofing membrane
2 Membrane attachment method Adhered
3 Insulation attachment method Mechanically fastened
4 BauderPIR FA Flatboard Rigid polyurethane foam board faced on both sides with aluminium foil
5 BauderSYN DB-PE 100 Air and vapour control layer (AVCL)
6 Bauder PIR infills Loose laid PIR infills to height of existing ribs of metal roof
7 Exisiting Substrate Existing Profiled Metal Roof