As part of the roofing refurbishment of Bury College’s plant rooms, this leading higher education facility near Manchester was looking for a roof waterproofing solution for a challenging application that featured extensive heavy plant detailing.
Lancashire-based roofing contractors, Surface Protection, were briefed to refurbish the existing roof. Originally asphalt, the roof had later been felted with additional plant added in various stages. This had rendered the felt ineffective. As well as this, the roof had recently been covered with a single ply membrane that had been unable to cope with the amount of detail required in sealing against all of the trunking and supports. There was also a row of low-level windowsills that had never been successfully sealed.
Poor drainage had caused the roof to hold inches of water after each rainfall and during the installation, the team at Surface Protection spent many hours vacuuming water in-between coats after overnight rain.
SIKA LIQUID PLASTICS SOLUTION
The team also had to overcome a number of logistical issues during installation, namely that every support had to be jacked up individually to allow the membrane to be dressed underneath. The team achieved this by pre-treating the Sika carrier layer with the Decothane roofing system, allowing it to dry, and then sliding it under supports so that each support could be lowered immediately. The pre-treated piece was then merged into the main rain covering.
The extent of plant detailing resulted in access being so limited that at times operatives were required to lie on the roof under the trunking, being passed small pieces of waterproofing to apply to various areas.
Surface Protection’s Jim Kennedy comments: “We needed to provide a modern waterproofing solution that was able to cope with the intricacies of the heavy plant detailing. This led to the specification of the Sika Liquid Plastics system, its elasticity and flexibility suiting the requirements perfectly.”
Furthermore, in keeping with English Heritage’s requirements, a mineral grit finish was applied to the covering, to mimic the tone of the original asphalt. This additional layer of slate chippings also afforded the roof slip resistant properties, an important health and safety feature for those working to maintain the building.