The Highwood apartment development in Horsham was designed by Berkeley Group and consists of over 1,100m2 of mansard roof and balconies that required a high-performance and durable waterproofing finish.

Having been working closely with Polyroof for nearly two decades, Berkeley specified the Protec system for its proven performance across all flat roof and balcony applications.

The key advantages of the Protec system for this application were:

1. Toughness – the finished membrane is exceptionally tough and hardwearing, greatly reducing the risk of damage from other trades after the system has been installed
2. Flexibility – no matter the size or complexity of the roof, Protec forms a seamless membrane and flexible membrane
3. Speed of installation – the RapidCure technology within Protec means the full system can be installed in hours, rather than days, keeping labour costs and disruption to a minimum

A key requirement was a highly efficient thermal performance for the mansard roof area, but the height of the insulation required to achieve the U-Value presented a design challenge. Working with Polyroof Technical Services, a roof design was proposed that featured insulation above a vapour barrier as per a standard warm roof build-up, but with additional insulation also present between the joists. To ensure that condensation would not be an issue, Polyroof carried out thermal calculations and condensation risk analysis which showed the dew point would not be reached within the roof build-up.

Roof build-up

Throughout the works Polyroof Technical Services carried out contract monitoring and regularly reported to Berkeley Group on the progress. This ensured that works were carried out to specification and that on-site challenges were dealt with swiftly before issues arose.

The finished roof and balcony areas allowed Berkeley Group to achieve the aesthetic and performance standards demanded for the project whilst enjoying the peace of mind from Polyroof’s trusted 20 year insurance backed accredited system guarantee.