Mastic asphalt roofing is often specified for the conservation of some of the UK’s most prestigious heritage buildings and roofing contractor and Mastic Asphalt Council (MAC) member – Infallible Systems – has recently completed a highly impressive application at the Parliament Offices in Cannon Row, Westminster, London.

With a Grade II listing, it was crucial to specify a roof waterproofing solution that would complement the building’s historic roof. The existing roof waterproofing was mastic asphalt that had been in place for over 30 years and it was decided that it was once again the most suitable solution to retain the roof’s original appearance whilst providing effective waterproof protection.

The new specification, written by Purcell Architects, involved removing the existing asphalt waterproofing and laying mastic asphalt nominal 20mm thick in two 10mm coats on black sheathing felt separating membrane with associated details and finishes.

Security was the biggest challenge on this project and checks on the whole Infallible Systems team were so extensive that they took over two months to gain passes. During the contract, extensive daily checks were carried out on the Infallible Systems lorry, which involved sniffer dogs checking the transport, the lorry being scanned and tracking of routes. Once the driver was in the cab, the doors of the lorry were sealed with tape and if the seals were broken on arrival, it wouldn’t have been possible to gain access. On arrival, the roofing installation team were guided by armed police who checked that the seals were not broken and escorted into the work area.

John Chapman, Director of Infallible Systems said: “In all our years of completing roofing contracts, this project had the most intense security measures of all and getting involved in a waterproofing project of a prestigious building such as the Parliament Offices is not a usual occurrence for a roofing contractor.

“This is an iconic building with fabulous architecture. There were many different large and small roofs scattered around which made the access extremely challenging. We had up to six operatives just for material hoisting and carrying at different locations. Workmanship had to be the top quality to match the strict requirements of what is a very unique building. Unfortunately photographs weren’t permitted of the finished roof but it is a project we are very proud of,” he continued.

Over the years, Infallible Systems has applied mastic asphalt to many prestigious heritage buildings and structures such as Tower Bridge, Hurst Castle, Tower of London and Hampton Court. On conservation projects, sustainability is often a prime consideration and when mastic asphalt has reached the end of its useful life, it can be recycled or used as roof screed. The Building Research Establishment (BRE) has officially stated that asphalt roofing is capable of lasting 50-60 years, but MAC has many examples well in excess of this.

Back in 2008, the Mastic Asphalt Council (MAC) made history as the first industry in the world to achieve the CarbonZero standard. Since then mastic asphalt has offset thousands of tonnes of carbon dioxide – underlining its status as a green waterproofing material. Mastic asphalt can help specifiers to achieve the highest BREEAM rating possible as mastic asphalt can be integral in any building design where an A+ rating is required.

This article featured in the October Edition of RCi magazine – click here to take a look.