When the existing flat roof above the International Departure Lounge at Gatwick Airport’s North Terminal was failing, Kemper System’s liquid applied waterproofing was the first port of call.
Working closely with contractors, Mitie Tilley Roofing Ltd, to develop a sound waterproofing solution, Kemper System’s Stratex Warm Roof system was specified using its solvent-free Kemperol 2K-PUR liquid waterproofing as part of a full refurbishment of the 2,500 sq. m roof area.
Severe water ingress into retail and restaurant units below meant the project was time critical to prevent any further issues as well as potential loss of profit for retailers. Chosen for its odourless, quick application and versatile qualities, the fleece-reinforced, liquid waterproofing system by Kemper System meant contractors could adhere to the strict timescales and operational restrictions on-site.
Mitie Tilley Roofing Ltd first removed 250 tonnes of the existing roof ballast using a suction excavator machine. The substrate was cleaned prior to an application of Kempershield Type 1 Primer and Kempershield Vapour Barrier. A combination of 123mm Kempertherm FR and Kempertherm TR Tapered PIR Insulation Board was installed onto the main roof area, including the guttering. Kempertherm TR comprises of a rigid PIR insulation board, a dense closed cell structure with a hard-top facing providing additional reinforcement to the top face that also provides the optimum substrate for the application of the liquid membrane.
The polyurethane-based Kemperol 2K-PUR resin was then applied in a single, wet-on-wet process. The roof area presented numerous complexities and lots of detailing, including five, large air-handling units, adjacent glazed facades and 36 separate large plinths with their own steel work, cable trays and pipe supports.
Prior to application, contractors also removed the existing lead skirts, cover flashings and associated cementitious insulated upstands on each of the 36 support plinths. The plinths, and more than 150 rain screen support steel work, were also primed before application of the fleece reinforced Kemperol2K-PUR resin.
The versatility of the Kemperol system and ease of application meant contractors could provide a watertight, seamless membrane that fully incorporated all of the flat areas, complex details and outlets on the roof structure.
Increased security measures also presented challenges on-site as the 15-year old building, which was an extension of this original airport terminal built in 1987, is at an airside location – further reinforcing the importance of minimal possession times.
Much of the refurbishment works were completed overnight within a four-hour working window as the client requested no disruption to the many retailers within the North Terminal below, which was done with ease using Kemperol. Kemper System also developed full Inspection and Test Plans (ITP) and Inspection and Test Records (ITR) which were updated daily by contractors, and field technicians from Kemper System who visited the site on a weekly basis to ensure compliance and maximum quality during installation.
Demonstrating first-class delivery within a live airport environment, Mitie Tilley Roofing Ltd and Kemper System won an award in the Liquid Applied Roofing and Waterproofing category for their work on the project at the annual NFRC (National Federation of Roofing Contractors) UK Roofing Awards (May 2017).
Warren Stuart, aviation director at Mitie Tilley Roofing Ltd, said: “This was a challenging refurbishment as the client demanded the highest of QHSE (Quality, Health, Safety & Environment) standards within tight timescales. The project also required a leak free installation, guaranteed for 25 years with zero defects and absolutely no standing water on the roof. Installation also had to be flame free, environmentally friendly and odour free due to the five air-handling outlets on the roof. The timescales involved on this project were also extremely challenging, allowing less than six months for this intricate roofing project. Kemper System ticked all the boxes.
“Having installed Kemperol before, we knew it was quick and easy to apply as well as versatile and durable. Its wet-on-wet application meant possession times on-site were also decreased. We worked closely with Kemper System’s technical team during five months of planning prior to work starting, and throughout the project. Thanks to the highly experienced and knowledgeable team, we were able to successfully deliver on time and within budget.
“Operational continuity was another major factor and thanks to the speed of installation and efficient programme of works, the airport’s retail units did not experience any ‘down time’ due to the refurbishment. To be recognised for this project at the UK Roofing Awards is a fantastic accomplishment and the professionalism and expertise of Kemper System helped us to achieve this.”
Stuart Hicks at Kemper System Ltd, added: “Kemperol 2K-PUR was specified for the project at Gatwick Airport because of its speed of application, solvent-free and odourless qualities. The system has also now been specified for the ongoing refurbishment works. It not only provided the benefits required to maintain the operational integrity of the terminal and time saving, but 80% of the applied polyols (resins) are obtained from renewable sources, adding to the green credentials of the project.
“We were delighted to be recognised at the UK Roofing Awards winning the Liquid Applied Roofing and Waterproofing category for this project, which required a reliable waterproofing system and the skill of the contractors to deliver it successfully.”