Bauder Building Board

The specification 

Bauder Total Roof System (BTRS) was specified for this project as it achieves a B_ROOF (t4) fire rating and the 8.2mm underlayer and cap sheet provide a robust, durable and extremely tough waterproofing system. Incorporating cellular glass insulation, BauderGLAS as it provides exceptional incombustibility and superior compressive strength. Using a tapered design scheme ensured proper drainage of rainwater from the rooftop. 

Although not part of the original design, a solar PV array was proposed to maximise the large roof area and generate as much output as possible.

Project challenges

The Burrell Collection is a Category A listed building which meant that existing, unmovable rooftop features had to be preserved. Because of the nature of their design, these details would create detailing challenges. The current roof also had insufficient drainage falls, and some roof areas were showing extremely high levels of water ingress where the existing insulation was saturated. With no capacity for additional outlets, a drainage solution was required.
Furthermore, the requirement for the renovation works meant that the replacement roof would need to serve as a thoroughfare for following trades moving and storing materials to refurbish other elements of the building envelope.

The roof works were completed before other trades who subsequently used the new roofing system as a thoroughfare for getting materials to their areas of the building. As such, utilising a bituminous system was the sensible option for this project as a single ply membrane would potentially have suffered damage due to the heavy foot traffic and debris of the follow-on trades. The sequencing of works was well managed by the installing roofing contractor, WG Walker.

There was no provision for additional outlets, so to ensure sufficient drainage, a tapered insulation scheme was specified. As the existing glazing and perimeter line of the building could not be raised, changing the insulation from BauderPIR to BauderGLAS meant that the initial U-value was reduced in order for the new tapered design to be successful. Due to the A-listing of the building, special dispensation was given in this instance. Tapered BauderGLAS was a new system for some of the operatives, so it was important to all parties that training was given to operatives onsite.

For most roofs, the addition of solar PV would pose many design considerations such as the weight addition to the structure or detailing challenges that could affect the integrity of the roof. However, using BauderSOLAR with its unique non-penetrative installation technique, this was a safe, secure and attractive addition to the project and a total of 384 units were installed to the waterproofing to provide an estimated output of 112.5mWh/a.

The result

The original single ply specification from another manufacturer was changed to a Bauder bituminous system with BauderGLAS insulation for several reasons:

• Understanding of Fire Protection and Standards – the safety and protection of the building against fire was imperative for the client and the insurers of this listed building and Bauder demonstrated in-depth understanding of fire safety standards and could deliver a fully guaranteed, A1 Euroclass  rated, non-combustible solution.

• Durability of Waterproofing System - The Bauder Total Roof System (BTRS) is a dual layer waterproofing system which is robust, durable and extremely tough. Ideal for the nature of this project as regular daily foot traffic from follow on trades had the potential to damage each roof after completion.  Although Bauder has a single ply system to match the original specification, the category type of waterproofing was not ideal to sustain the expected levels of access and would have placed the waterproofing at risk to damage.

• Technical supportive information – Bauder could provide all technical data in a timely manner.

• Onsite support and monitoring of works – Bauder’s rigorous inspection regime throughout the duration of the project delivered confidence for the client.

System installed

Bauder Total Roof System (BTRS) with BauderGLAS insulation