Waterproofing A Grade 2 Listed Theatre, North Wales

dcb1960
21 hours ago
2 min read

Theatr Clwyd was built in the mid-70s to house both theatre and TV production. It is still Wales’ main producing theatre. Situated in the hills above the town of Mold, the Grade 2 Listed structure needed urgent reconfiguration and upgrading. The aim was to expand its cultural role and deliver a performance, music and communal space for North Wales. Architect Haworth Tompkins aimed to repurpose the existing fabric. By demolishing only where necessary, they would also hit a whole life zero carbon target.

Empty movie theater with vibrant red seats, dim lighting, and a dark carpeted floor. Walls have subtle geometric patterns. Quiet ambiance.

Project Scope

The project included completely stripping out, refurbishing and remodelling the existing buildings. A new-build timber foyer extension was also added. Main contractor Gilbert Ash appointed Specialist Contractor Stonehouse Waterproofing for the multi-phase project and the process of waterproofing a Grade 2 Listed theatre. The project required varied waterproofing strategies, from existing below-ground structures to new proposed retaining elevations and sections of the new build extension.

Construction site with a foundation wall coated in black sealant. A bucket labeled "Hydrobond 2K-Flex" is nearby. Blue sky with clouds. — External detailing using HydroBond 2K-Flex

New-Build Foyer and Workshop

Newton’s external, pre-applied sheet membrane HydroBond 403 was chosen to protect the ground-bearing slabs and partially retaining elevations. The flexible and reinforced bitumen coating HydroBond 2K-Flex was also used externally for all detailing elements. Finally, a combined Type A waterproofing system was achieved using the flexible, cementitious HydroCoat 107 Elastic 2K internally as a secondary barrier.

Empty cinema with rows of vibrant red seats, dim lighting, and dark walls, evoking a quiet, expectant mood.

Existing Basement Cinema

The existing concrete basement was already suffering from water ingress. Stonehouse therefore specified a full CDM System to deliver Type C waterproofing protection. Utilising the CDM 508R, an 8mm cavity drain membrane and gas barrier, Stonehouse installed the system across the ground bearing floor slab and to three retaining elevations. Water captured by the system is drained out using CDM BaseDrain and FloorDrain through the only open elevation and into the existing clean water drainage.

Lift Pit Waterproofing

The six lift pits across the site required their own approach. First, Stonehouse used HydroBond 403 to the lift pit base prior to concrete casting. Next, HydroBond 2K-Flex was used to coat the external concrete surface. Finally, HydroCoat 107 Elastic 2K was used as a flexible, internal Type A membrane.

People gather outside Theatr Clwyd, a modern glass-front building. Lush greenery and vibrant flowers accentuate the lively atmosphere.

The Result

Stonehouse have a history of designing and overseeing high quality projects, and a highly experienced team of qualified waterproofing surveyors. Using our advanced product range they delivered Theatr Clwyd’s waterproofing on budget, on schedule, and ready for curtain up.