The roof of an occupied 1930s art deco municipal office building, situated in the busy town centre of Blackpool, Lancashire, required urgent repair.
The building was experiencing standing water on a largely zero falls roof with only four drainage outlets, meaning water had started to leak into the occupied offices below.
Kemper System’s Stratex Warm Roof system using its Kemperol V210 was specified for the 1,200m2 roof area, which was supplied as a complete integrated system of matched components.
The Kemperol V210 is a polyester-based resin, applied wet-on-wet that forms a permanently elastic, seamless, yet highly durable waterproofing membrane.
Due to limited access on site, Lancashire-based Castle Contractors had to remove 40 tonnes of stone ballast and inverted insulation on the existing roof by hand. Because of the volume of material and the busy street location of the building, skips were not suitable to dispose of the waste, so the material was lowered from the roof and then immediately taken away from site using contractor’s vehicles.
The roof was complex with detailing around air-conditioning units, raised steelwork and cable trays in close proximity. Contractors also removed and replaced eight rooflights and boxed-in others that were no longer required. All existing steel work on the roof was treated and encapsulated with plywood and waterproofed with Kemperol to ensure additional lifespan.
Contractors had to clean the roof prior to the application of Kemper System’s Kemperol V210. The lack of drainage meant any power washing created more ponding on the roof. Therefore, contractors used a vacuum wash and dry system that automatically extracted the waste water and pumped it directly down the drainage outlets.
After cleaning the substrate, contractors applied Kemper System’s Kempertec D Primer over the Kempertherm F insulation as part of the warm roof build-up. The insulation is rigid PIR board with multi-layer foil composite face on both sides, and has tongue and groove edges for interlocking construction. Kempertec EP5 Primer was also applied prior to installation of Kemperol V210 to the roof deck and stairwell areas.
The cold-applied Kemperol V210 liquid resin saturates a non-woven reinforcement fleece that is tailored to the exact contours and details of the roof. The waterproofing is installed in a single process and cures to provide a robust waterproof membrane that cannot delaminate and is UV-stable.
Mark Atherton, managing director at Castle Contractors, said: “There were three main challenges to overcome on this project: the safe removal of the existing ballast, cleaning of the roof prior to application and the creation of drainage channels to carry water to the outlets.
“Due to budget constraints preventing the use of a full tapered insulation scheme to improve the drainage, it was agreed by the client, Blackpool Council, for us to create a 50mm deep channel system in the warm roof build-up to route all the water to the four drains that serve the entire roof.
“Because Kemper System is applied wet-on-wet, we were easily able to waterproof the entire roof area including the new drainage system, and execute complex detailing around the roof lights with ease.
“Access to site was extremely challenging so the simple yet effective equipment required on site was ideal.
“Thanks to the successful application of Kemperol and on-site technical guidance, we were able to develop a good relationship with the client for future projects.”
Stuart Hicks at Kemper System added: “Despite the challenges faced by Castle Contractors, the project was completed ahead of schedule thanks to the quick and easy application of the Stratex Warm Roof system and our Kemperol V210 liquid waterproofing system.
“The project was shortlisted for the Liquid Roofing and Waterproofing Awards due to the complexity of the roof which made this an ideal project for a liquid applied membrane, the technical solution offered, and the difficulties experienced with site preparation and logistics.”