Specifier Review
Kemperol - Lewisham Hospital

Full Recovery of Lewisham Hospital Roof with Kemperol

KEMPER SYSTEM’s KEMPEROL® 2K-PUR solvent-free and odourless liquid waterproofing system has been used to refurbish the roof of Lewisham Hospital’s main entrance and outpatient department.

Ensuring the project avoided any disruption or nuisance to staff and patients in the unit or the surrounding wards, the cold-applied solution was installed on the 1,600sq. m. roof area by contractors, Noble House Services (UK) Ltd.

The existing felt roof above the main building had failed and so KEMPEROL® 2K-PUR system was selected to provide a durable and long-lasting waterproofing solution at the hospital.

Contractors first cleared the roof of all redundant services, removing as much a feasibly possible without causing disruption to the running of the hospital. The existing asphalt roof was then cleaned and KEMPER SYSTEM’s KEMPEROL ® 2K-PUR was applied directly to the existing roof coverings in a single wet on wet process.Kemperol - Lewisham Hospital

Reinforcement fleece was laid directly onto the first application of wet resin, immediately followed by more resin on top to ensure complete saturation of the reinforcement fleece. This provided visible assurance the correct amount of resin had been used throughout, and a consistent depth of coverage and membrane thickness is achieved. Once cured, the system forms a seamless, elastomeric waterproof membrane that cannot delaminate, is UV stable, and creates a strong bond directly to the substrate.

Contractors then installed a closed-cell, 160mm extruded polystyrene (XPS) insulation board before installation of concrete faced 50mm insulation board, followed by paving slabs to the perimeters to add additional ballast to the inverted roof build-up.

The roof area had a number of complexities with many ventilation outlets, up-and-over staircases and walkways, steel beams supporting the units on the roof, as well as upstands and roof hatches for access. Because KEMPER’s waterproofing system is roller-applied, operatives could easily install the resin underneath the units and around the complex roof structure.

Thesolvent-free and odourless qualities of the KEMPEROL® system also meant minimum disruption at the hospital throughout the application process. No hot works were required as part of the refurbishment, further reducing potential health and safety risks, and no wait time between applications of resin.

The roof area which needed attention was above the main entrance as well as Radiology, Cardiology and MRI departments – all very important sections of the hospital building. Refurbishment of the roof using KEMPER SYSTEM has provided higher thermal performance and energy saving benefits for the building. The hospital estates team were extremely pleased with the finished project which was completed on time and within budget.

Contractors were able to install the KEMPEROL® liquid waterproofing System quickly and safely despite the complexity of the roof area.

Gerry Ogborn from Noble House Services (UK) Ltd added: “We didn’t experience any issues when installing KEMPEROL® 2K-PUR. This project could have presented a number of problems and time delays if an alternative roofing material was specified, but it was not only easy to transport with minimal materials and apparatus to carry, but the liquid-applied resin meant we could get underneath and around the complex roof structure and detailing with ease.”


Kemper System Ltd
Kemper House,
30 Kingsland Grange
Woolston, Warrington
Cheshire, WA1 4RW, UK
Phone: +44 (0)1925 445532