Approximately 450m² of HARDROCK Multi-Fix Recovery Board has been installed by main contractor Roofing Technologies to resolve the problem of occasional roof leaks at Llanfair Primary School in Cowbridge, Wales.
It was recognised that the leaks were coming through the existing PVC single-ply membrane, the council recommended that the roof should be overlaid with a more robust bitumen membrane system. This would avoid leaks in the future, and also provide much needed acoustic insulation.
However, this presented the contractor with a challenge, as PVC must be isolated from any form of bituminous product and would therefore require a separating layer to create an appropriate surface in which the bitumen could be applied to. Having been on site to maintain the roof numerous times in the past, it was important for Roofing Technologies to find a long lasting solution.
Ben Murphy, director at Roofing Technologies, commented: “The product which was originally recommended would not have been compatible with the current roof surface and would have required the existing waterproofing system to be stripped, which can be an expensive and problematic option as the building would need to remain water tight at all times.
“It was our aim to find a cost effective alternative. After hearing about ROCKWOOL’s new flat roofing product, we specified its HARDROCK Multi-Fix Recovery Board.”
Roofing Technologies agreed the delivery time and method before getting on site, which resulted in the project being completed within five weeks.
The HARDROCK Multi-Fix Recovery Board was specified to act as the separating layer between the new and existing membrane systems. As the bitumen would be applied using a roofing torch, the separating layer had to be compatible with this form of application, and provide a safe, non-combustible roof surface to bond too.
Specially developed for use on flat roof refurbishment projects, the recovery board was extremely quick and easy to install. It was fitted directly over the in-situ roof membrane and evened out imperfections on the existing external finish. While there is an option to install the board using either adhesive or mechanical fixings, Roofing Technologies opted to fit it with the latter.
Mr Murphy added: “As we were using mechanical fixings for this project, we required additional product and installation information, such as the amount of fasteners needed and where to fix them. We were impressed that a ROCKWOOL technical representative visited us on site to provide the required support with datasheets and in-depth knowledge. This technical support was a huge benefit to us, and sped up the installation process in the end.”
This product has provided the building with excellent acoustic properties, improving the sound insulation performance of the existing flat roof system by 25%. At the same time, the overlay board has evened out the surface, improving the aesthetics of the roof.
The Llanfair Primary School project required a quick to install and affordable solution, which would prevent the roof from leaking and provide acoustic insulation.
The ROCKWOOL product has helped to achieve this, and will avoid extensive maintenance in the future. Not only has the solution met all the key requirements, but its non-combustible properties meet the highest European fire classification performance, achieving an A1 rating.
