A service-led approach to the addressing a failing warm roof system at Circle Health Group’s The Cavell Hospital, with a roof survey and moisture scan indicating that only 20% of the roof actually required full strip and replacement, has saved the private healthcare provider around £900,000 by eliminating the need for full replacement, and the associated requirement for new roof-mounted plant and equipment located in Enfield, The Cavell Hospital is a key facility for Circle Health Group.
The building’s existing mastic asphalt roof, spanning over 1,000 m2, had reached a critical state of disrepair, with water ingress and internal damage. Faced with a significant refurbishment challenge, Circle Health Group turned to long-term partner, Garland UK, which was able to deliver a durable, cost-effective waterproofing solution that aligned with stringent budget constraints and compliance standards.
Extensive Water Ingress The existing warm roof system, composed of mastic asphalt over mineral wool insulation, exhibited widespread failure. Thermal shock had caused surface shrinkage and cracking, particularly around internal gutters and service penetrations. Water ingress was widespread, and several plant installations penetrated the waterproofing system, further complicating refurbishment efforts. Initial projections suggested the replacement of roof-mounted plant equipment could increase the total project cost by up to £1 million.
Project Cost Saving Garland UK’s Technical manager, Alex Kitis, firstly implemented a detailed roof condition to provide clear and accurate data for targeted specification. A comprehensive moisture scan revealed that just 20% of the roof required full strip and replacement, while under 50 per cent of the existing substrate could be retained under Building Control repair rules, avoiding a full thermal upgrade.
Crucially, the survey enabled the project to proceed with minimal disturbance to the plant equipment. Instead of a full removal, strategic isolation of plant units allowed for works to proceed with only minor relocation, reducing plant-related costs to under £100,000, a saving of over 90%. The savings were made possible by the Dura-Coat system’s ability to be easily applied under and around complex plant penetrations without the need for disassembly, making it ideal for intricate roof layouts with heavy detailing.
Garland’s Dura-Coat PUMA liquid waterproofing system was the ideal solution for overlaying the remaining sections of the existing roof, thanks to its effective crack-bridging properties and rapid 30-minute curing time. For stripped areas, a new build-up incorporating a vapour barrier and 120 mm PIR infill insulation with tapered insulation to the gutters was installed to promote water run-off through the congested internal gutters.
Garland said: “Installed by approved contractor, Evolution Contracts, the system provided a seamless, high-performance waterproofing layer with superior flexibility and durability, perfectly suited to the busy hospital environment.” All works were fully monitored under Garland UK’s rigorous quality assurance program, with twice-weekly site inspections and full digital reporting via the RAMP (Roof Asset Management Programme) portal.
Long-term guarantee The roofing specialist says the completed project delivered a watertight, compliant roofing system on time and on budget. Through expert diagnostics, collaborative planning, and a high-performance Garland system, Circle Health Group ensured the hospital could remain fully operational throughout the works, avoided significant cost escalations, reduced risk, and secured the long-term performance of a vital clinical building.
Alex Kitis added: “This was a complex and highly constrained project, where every decision needed to balance clinical operational needs, structural performance, and financial limits. Our goal was to develop a solution that delivered maximum value for the client, not just for today, but for the life of the building. We’re proud to have supported Circle Health Group in achieving the best possible outcome for both the building and its business.”
