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Waterproofing A Grade 2 Listed Theatre, North Wales

    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.

    Waterproofing A Basement Swimming Pool And Cinema In Tunbridge Wells

      Newton Specialist Contractor MJ Rooney undertook this extensive basement construction project beneath a period Georgian property in Tunbridge Wells, Kent. Working alongside designers from Open Architecture and Croft Structural Engineers, the MJ Rooney team needed to carry out deep and large-scale excavations.


      Modern indoor pool with blue water, lounge chairs on the side, and skylights above. The stone walls add to the calm, minimalist ambiance.

      This included significantly extending the existing basement beneath the period property and the rear garden, whilst retaining the original structure above with minimal disturbance. The scale of the basement extension included the existing Georgian basement and the area beneath the garden.


      Construction workers in front of a large house renovation project, with scaffolding, ladders, and excavated site, under a clear blue sky.
      The scale of the basement extension included the existing Georgian basement and the area beneath the garden

      Robust Temporary Works

      Complex temporary works were designed to support the house on stilts during the excavation. Steel sheet piling was also essential to provide support around the site. However, this wasn’t without its difficulties. The deep excavation works took place within the water table, and restricted site access was problematic for both the piling rig and during the new basement construction. Deep excavations were required into the water table in order to achieve the required depth for the new basement swimming pool.


      Empty indoor pool under construction, concrete walls and floor, scaffolding and broom visible. Bright overhead lights, industrial setting.
      Deep excavations were required into the water table in order to achieve the required depth for the new basement swimming pool

      Project Scope

      The large-scale new basement area was to include a swimming pool, leisure area, sauna, steam room, and cinema. All areas therefore needed to be completely dry, defined as a Grade 3 environment by BS 8102:2022. This required a waterproofing design that would account for the specific requirements of the site environment and the structure. The new basement area included a combination of existing underpinned structure and new reinforced concrete.


      Construction site with metallic beams, concrete floor, and scaffolding. Workers in safety vests discuss plans under bright, hanging lights.
      The new basement area included a combination of existing underpinned structure and new reinforced concrete

      The Solution

      The primary solution was a full internal cavity drain system utilising Newton's comprehensive CDM System. But first MJ Rooney primed all concrete surfaces with CDM 906 Lime Inhibitor to prevent any ‘free lime’ from affecting the CDM System. CDM 508 membrane was then installed to all walls to capture water. The CDM 520 eco Floor membrane also provided high volume drainage capacity across the floor. A perimeter drainage system using CDM BaseDrain delivers any captured water to a Titan-Pro sump chamber with dual pumps for safe and reliable water removal.


      The Result

      MJ Rooney’s meticulous approach ensured minimal disruption to the residence while delivering a high-quality, functional new basement in compliance with BS 8102. They also demonstrated their capability by supporting the installation with a 10-year insurance-backed guarantee.


      Home theater with grey recliners facing a large screen showing two people near a building. The room has dim lighting and a modern design.

      Testimonial

      “MJ Rooney were extremely professional in every respect. They completed a first-class construction job. I would recommend and use them again.”


      Newton Specialist Contractors

      Newton always recommends that it's systems are installed by one of it's nationwide network of Newton Specialist Basement Contractors (NSBCs). All members of the network adhere to strict criteria and are required to demonstrate quality workmanship, resulting in a meaningful scheme that provides unsurpassed technical excellence.


      Newton Specialist Contractors can also act as the waterproofing designer on your project, taking on the liability under their professional indemnity insurance. Finally, they also offer insurance backed guarantees to support their installations. For further information on Newton's specialist contractors, please speak with a member of the Newton team. Call 01732 360 095 or email tech@newtonwaterproofing.co.uk  www.newtonwaterproofing.co.uk

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