Hong Kong International Airport Roof Repair

The existing waterproofing system at Hong Kong International Airport Terminal 1 was found to be damaged. It consisted of 1.8 mm thick PVC membrane which was fixed on the composite roof decking by tie bars. The Hong Kong Airport Authority decided to install an additional waterproofing membrane on top of the existing system without removing the existing membrane in order to provide a durable new waterproofing system. The whole re-roofing project covered an area of 200,000 m² with a target completion date in 2016.

The project included the design, supply and installation of an additional roof waterproofing membrane on the top of the existing PVC sheet membrane waterproofing system of Terminal 1 roof. The loading of the additional waterproofing system to be imposed on the roof was not to exceed 2.5 kg/m², while its fixing system needed to satisfy the design wind pressure with the highest figure 8.5 kPa. Moreover, seam welding was mostly done by handheld welding guns instead of automatic machines. This was due to the dome shape profile of the roof where automatic machine could not be implemented.

Sika Sarnafil® S 327-15 L was laid on top of the existing membrane by mechanically fastening it to the metal deck. The  membrane was clamped by polymeric batten strip, Sarnarail and stainless steel fasteners. Sarnafil® Metal Sheet and Sikaflex® AT Sealant were installed along the roof edge profiles and skylights. Sikaflex®-265 was applied to all skylight joints, totaling over 20,000 m of length. Sikaplan® Walkway was installed as maintenance protection.

Sarnafil® 327-15 L
Sarnafil® Metal Sheet
Sikaplan® Walkway
Sikaflex® AT Sealant
Sikaflex®-265