The existing flat roof waterproofing system above the international departures lounge at Heathrow Airport’s Terminal 3 had reached the end of its useful life and was experiencing internal water leaks. Main contractor Vinci Construction instructed roofing sub-contractor Mitie Tilley to commence with the removal and replacement of the existing waterproofing system.
Mitie Tilley were faced with the challenge of putting together a roofing specification that had to accommodate a number of requirements:
At a busy airport, the internal functions of the departure lounge could not be interrupted. This included interruption from water leaks or smells. The proposed system had to be completely flame free to reduce the risk of fire. The system needed to be sufficiently flexible to accommodate the large amount of plant and equipment on the roof, and both winter and summer time working had to be considered.
The existing waterproofing system had to be removed from the roof area at one designated point which needed to be co-ordinated properly with the airport to avoid affecting passengers and airport staff.
All product deliveries had to be first booked in at an offsite facility for security screening prior to delivery to site.
Elastoflex Solvent Free Liquid Waterproofing membrane was chosen and the specified warm roof system included Micoral SK self-adhesive vapour control layer, Thermazone Roofboard PIR insulation and Pyrobar self-adhesive underlay as the carrier membrane.
The inclusion of the Pyrobar Underlay permitted exposed areas to be waterproofed very quickly following removal of the existing membrane build up. As a result, adverse weather interruptions were kept to an absolute minimum and allowed work to continue during months of cold weather.
The Elastoflex Solvent Free Waterproofing Membrane offered the ideal solution to complete the waterproofing build up as no smells were generated upon application and awkward penetrations to plant and equipment supports could be suitably waterproofed.