The regeneration of London’s landmark Battersea Power Station is one of the largest urban developments of its type in Europe. The multimillion-pound project’s second phase confirms its description as a ‘mini city’, as it involves the creation of 250 residential apartments, 100 new retail, food and drink outlets, a 2,000-capacity events venue and 500,000ft2 of new office space. Tony Lawther at leading UK commercial roofing company BriggsAmasco, provides an overview of the company’s challenging delivery of a multiple-application waterproofing programme as part of the development that is destined to rejuvenate a long-overlooked area of south-west London.
Appointed by Battersea Power Station Development Company (BPSDC) and MACE, BriggsAmasco’s ingenuity and skills were crucial to ensuring three key elements of the project’s second phase were supplied with a watertight solution that excelled in terms of workmanship and sustainability. Our teams’ performance as part of the complex waterproofing programme led to BriggsAmasco winning the Mastic Asphalt category at the 2023 NFRC Roofing Awards.
Main Energy Centre
The power station’s main energy centre is pivotal to the Battersea Power Station development’s heating and cooling provision; hence a high-grade waterproofing system was essential to safeguarding its belowground service equipment. For BriggsAmasco, this meant us designing and installing a solution with sufficient durability to withstand heavy motorised traffic. We specified an IKO Permatec system with ultra heavy-duty protection installed over it. To protect this initial waterproofing layer, a 40mm-thick Road Specification IKO Permapark mastic asphalt system was installed; we had considered other options such as traditional tarmac or concrete, however these would 150mm-thick was deemed too dense for the task and ‘carbon heavy’. To ensure the mastic asphalt – a 100% CO2 neutral solution – was laid to the correct tolerance and at rapid speed, it was installed using a BriggsAmasco state-of-the-art asphalt finishing machine. The combination of asphalt over the primary waterproofing was an industry-first. It meant the belowground waterproofing’s protection layer could remain in-situ, thus saving removal and recycling costs, and environmental impact.
Grade II-listed chimneys
BriggsAmasco was also required to develop a system to re-waterproof the station’s landmark white chimneys, which were taken down and rebuilt in identical fashion. Environmental concerns led to our specification of IKO Permaphalt, rather than lead, for the task. This certified carbon-neutral product is the same waterproofing solution originally applied to the four chimneys decades ago, with the addition of advanced polymers to increase its performance. The material was applied to the chimneys’ base at a 20mm thickness across a 750m2 area in an application involving new and traditional installation techniques. BriggsAmasco exceeded its project remit by designing a mastic asphalt solution to waterproof and line a Peregrine Falcon’s nest, providing the resident birds with a 1m x 1m2 permanent home within the chimneys. The product was used as it is rot and vermin-resistant, as well as being waterproof and non-toxic.
Terrace waterproofing
In collaboration with the insulation manufacturers, BriggsAmasco devised a super-slim PIR/VIP panel to ensure a series of apartment terraces within the revamped power station achieved thermal requirements. In each case the waterproofing required minimal build-up to optimise floor-to-ceiling heights, hence the insulation needed to compensate its slim composition by demonstrating superb thermal performance. The resulting panel achieved a lambda value of 0.006 W/mK, eliminating the risk of cold-bridging for the long-term protection of the apartments. The panels were installed by BriggsAmasco as part of a waterproofing build-up finished with IKO’s GoldSeal Built-up Felt Roofing.
These large, complex elements of the programme saw up to 50 full-time BriggsAmasco operatives – which ranged from a specialist mastic asphalt installation team to a host of designers and project planners all assisting in the installation of 45,000m2 of waterproofing and insulation over the entire project.
Additional sustainable features innovated by BriggsAmasco as part of Battersea Power Station’s redevelopment included the company’s design, commissioning and installation of a series of sun tubes. The 8m x 1.2m stainless steel units will introduce natural daylight to significantly boost the low-carbon credentials of the receiving retail outlets. Overall, a further 8000m2 of IKO Permatec waterproofing was installed using our own fleet of zero-emission plant. IKO enertherm inverted insulation and sedum green roofs, were installed by BriggsAmasco across the project. Add comment about the use of all Electric plant
BriggsAmasco completed further detailing in the form of lead flashings and cappings, which were installed to the main power station building and apartment terraces. The waterproofing programme’s carbon-friendly aspect was bolstered by the use of locally-sourced products, 99.9% of which were manufactured in the UK.
The Battersea Power Station development brought all of BriggsAmasco’s well-renowned roofing skills to the fore. Logistically and technically, this huge project was the very definition of a specialist roof waterproofing application.
