Archetech Issue 36 2018 | Page 114

KEMPER SYSTEM FACILITATES AWARD WINNING ROOF REFURBISHMENT AT GATWICK AIRPORT 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 Kemperol 2K-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