The Old Pump Works

The Challenge

The Old Pump Works is a new-build residential scheme. Forming part of the development are two-storey apartment blocks each designed with curved green roofs to complement the rural landscape. To ensure a robust, homogenous waterproofing solution for the green roofs, WestWood’s Wecryl 230 PMMA-based resin was specified by Emperor Roofing Ltd.

The Solution

To the plywood substrate, the roofing contractor applied a vapour control barrier, 130mm of PIR insulation and carrier membrane followed by the fleece-reinforced Wecryl 230 waterproofing resin.

FLL certified, the Wecryl 230 PMMA technology is resistant to roots and rhizomes. Providing a flexible, seamless and durable membrane, the waterproofing layer accommodates post-build settlement and withstands the load bearing of the plants. 

To complete the roof structure, a specialist green roof contractor was appointed to install a drainage board and filter layer followed by a scientifically-engineered growing medium for the sedum blanket.

On either side of each apartment block are large flat roofs offering amenity space for residents.  Wecryl 230 was also selected to waterproof these areas ensuring a robust solution.   

The Outcome

The rapid curing qualities of the Wecryl 230 waterproofing enabled Emperor Roofing to respond effectively to adverse weather conditions.  The liquid membrane can cure in as little as 15 - 20 minutes even at sub-zero temperatures. By adding variable amounts of catalyst to the resin, the installation team could control curing times to suit their requirements.

The mix of sedum brings colour all year round while offering a low maintenance living roof solution. WestWood’s PMMA waterproofing was a vital component in the warm roof build-up, ensuring the green roofs remain watertight for at least 20 years and the risk of damage is eliminated even as plants mature.