Historic Restoration with Modern Methods
Project: Basement Waterproofing System
Peter Cox Glasgow has recently completed a large contract for Albany Interiors Ltd who specialise in interior refurbishment of shops and leisure centres. The project in Glasgow’s prestigious Buchannan Street shopping area was to provide an underground waterproofing system in the basement of a retail building which was home to sport-style company Puma.
Gary Bouse, Glasgow Branch Manager for Peter Cox in Glasgow said: “The building is over 100 years old and presented several challenges because although the front area, which had been used as bathrooms, is contained within the building, part of the front basement is below street level.
The main challenge was to find a way to fit an effective water proofing system to a flat ceiling and we had to use all of our technical expertise to develop a bespoke solution for this project.
On a more practical level, the parking restrictions meant we could only drop off materials once, early in the morning, and then we had to walk them underground the full length of the shop to put them in place. It meant a lot of very careful planning on our part!
On inspection of the basement, Gary and his team found everything to be soaking wet and stinking. The whole area had to be stripped down in order to present a blank canvas for the team to work and install a full waterproofing specification including the installation of a cavity drainage membrane system incorporating Peter Cox Drywall Damp Proof Course, Lining Frame, Plasterboard lining and the formation of a unique sloping soffit and a floating floor.
The work was carried out to British Standard 8102:2009 which identifies that a drained cavity system is the safest method available for those seeking maximum assurance against system failure. This is because ground water is controlled, diverted and harmlessly removed rather than being ‘’blocked’’ at the point of entry. Consequently the risk of increased hydrostatic pressure is reduced, whereas directly applied systems generally increase the level of hydrostatic pressure imposed on the structure.
The key to any successful directly applied render system is the preparation of the substrate. This mechanical preparation is not only a risk, but is expensive and destructive to the substrate. Cavity drained membranes however, require little and sometimes no preparation.
The cavity drained system is designed to control both water vapour and the penetration of ground water. Once the system is in place, three main functions are achieved. Firstly, the system controls vapours, secondly damp pressure is equalised and thirdly, the system will act as a drained cavity system, controlling water ingress.
Cavity drainage systems work on the principal that any water entering on the “wet” side of the system is either drained away to a sump chamber and pumped to a drainage point or where local conditions allow (not suitable for hydrostatic situations), by natural drainage. The cavity drain system that we installed was a sealed system with natural drainage across the existing floor, enabling water to collect into a sump chamber where it shall be pumped to an external drainage point.
Gary Bouse said: “The main problem for us was trying to install the system on a flat ceiling and so we designed and built a custom made sloping soffit, supported by plywood with timber joists underneath the plywood. The joists and plywood held up the membrane. We could then excavate the sub site to accommodate the installation of the sump chamber and the existing floor slab to accommodate the installation of an ‘aquaduct’ perimeter drainage. We then fit a submersible double pump, complete with alarm system and wired it into a fused spur box.
“An 8mm cavity membrane system was fixed to the wall surfaces with specialist fixings, using a sealed plug. The plug has a dual purpose; fixing the membrane system to the wall surface and allowing studding/battens to be secured without piercing the installed system. We also provided and fixed a 20mm floor membrane to join the wall membranes. The 20mm floor membranes provide greater drainage capacity and help prevent blockages due to a build-up of silt or lime which can occur with smaller size studs, in certain situations.”
The work was completed in five weeks and with minimum disruption to Puma, its customers and its neighbours.
Gary Bouse concludes: “Peter Cox Property Services carries out numerous water proofing systems across the UK and it’s true to say that they all pose different challenges.
However, as we have shown here, we have yet to find one that has beaten our experts!”
Peter Cox have extensive experience when it comes to installing tricky structural waterproofing solutions for historic buildings of all shapes and sizes. If you have a commercial structural waterproofing project that is proofing to be a bit of head scratcher, then Peter Cox are the experienced and qualified structural waterproofing contractor for you.
Call our expert team today on 0800 633 5712 or fill in our online contact form and we will get back to you.
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