Roundwood Park School

Bauderflex bituminous system with BauderSOLAR and Bauder rooflights


A number of the building’s roofs at Roundwood Park School needed refurbishing to prevent further water ingress entering the classrooms below. The client wanted the new waterproofing system to be of high quality and provide falls to the roof to help mitigate ponding water. A no capital outlay PV solution and new rooflights were also desired as part of the works to optimise the roofs functionality.

Bauder Building Board

Project: Roundwood Park School
Location: Harpenden
Project type: Refurbishment
Roof size: 5,200m²
Specifier: Wilby & Burnett
Approved contractor: Russell Trew Ltd
PV funding facilitator: Evogreen Plc

The specification

All the roof areas were waterproofed with Bauder’s reinforced bituminous system Bauderflex. The system build-up included Bauder’s highly efficient BauderPIR T G tapered insulation providing the required falls to the roof without incorporating them into the structure. 67 Bauder rooflights were also fitted providing essential daylight and ventilation to the building interior.

Bauder’s solar PV system, was installed consisting of 470 PV modules whose individual performance can be monitored online; enabling the school to generate at least 130.28 megawatt hours of solar power each year. Bauder worked with sustainable energy funding specialists Evogreen to ensure Roundwood can enjoy all the associated financial benefits of their PV system without any up-front capital costs.

Products applied 

Bauderflex system
This bitumious membrane is resistant to high levels of structural and thermal movement.

Bauder solar PV system
Our PV system was installed with 470 PV modules being fitted.

Bauder rooflights
Bauder rooflights are fully compatible with all Bauder waterproofing systems and hold BBA certification.

Project challenges

The school remained open throughout the project creating logistical challenges. However, all roofing works were timed not to cause any disruption to ongoing work at the school.


System installed

Bauderflex Bituminous System


1 BauderFLEX K4E Heavy duty elastomeric bitumen capping sheet,
2 BauderTEC SPRINT DUO 2mm thick technically advanced self-adhesive elastomeric bitumen underlayer with DUO lap technology.
3 BauderPIR FA-TE  Efficient PIR flatboard insulation board with aluminium foil facing on both sides. The top facing features a printed grid pattern to aid site cutting. It is lightweight and has zero ozone depletion potential.
4 BauderTEC KSD FBS  Self-adhesive elastomeric bitumen vapour control layer; mica finished upper surface for easy bonding of insulation in Bauder insulation adhesive.