When the basement area of a high-end shop in Chelsea was found to be inches deep in water, one too many times, the decision was made to resolve the issue once and for all.
As well as the resulting damage to the fabric of the building, frequent flooding meant that the basement area could not be used as a viable commercial space, so the tenant was losing potential income.
The building owner called on local commercial basement tanking experts Garratt’s Damp & Timber to survey the problem area and develop a solution that would allow the basement to be refurbished and operated as a viable asset to the tenant’s business.
In order to gain a clear picture of how to permanently waterproof the basement, Garratt’s carried out a flood simulation. This is a study into the points of intrusion of flood water to highlight areas of weakness and provide a foundation for creating a finite waterproofing solution.
The results highlighted that water was entering the basement via defects in the shop front and pavement light wells, travelling along a concealed steel joist and entering the centre of the basement. This presented several complications in finding a solution. The shop was located on a busy street in the centre of Chelsea where traffic was heavy, so replacing the pavement lights was logistically impossible.
The distance that the ingress of water was covering was so widespread that to effectively waterproof the entire area, the complete system had to be customised using a range of different products and processes.
The result was a bespoke waterproofing system that both maintained the integrity of the building and delivered a completely dry, Grade 3 internal environment that met the requirements according to BS 8102, the British Standard, relating to withstanding even the worst circumstances of water pressure and presence in the surrounding area.
The first process was to work with the main contractor, CJS, and remove the shop front to design a bespoke metal bund system that resolved structural defects and prevented further water ingress.
The concrete and steel framework were then treated with sealing primer and finished with three coats of a flexible cementitious waterproofing membrane. The shop front was then restored to the original.
The next stage was the installation of a Newton CDM System, which comprises BBA-approved cavity drain membranes, drainage conduits, sump chambers, pumps, and associated control and telemetry systems.
The dedicated sump chamber houses dual pumps that are controlled and managed by a control unit fitted with a battery backup, which will give additional peace of mind to the tenants who are probably living on the edge every time it rains.
Jack Garratt (CSSW, CSRT) - Consultant Surveyor for Garratt’s Damp and Timber, commented:
“Garratt’s were required to design and install a system to stop high volumes of water penetration through the pavement lights and walls on this tricky project. Replacing the pavement light was out of the question due to the busy street, and water was also penetrating the shop front and migrating along with steels to a point that was impossible to waterproof. Through close collaboration with the experts at Newton, we implemented a full system to withstand any future flooding.”
JN Newton Waterproofing is a UK leading supplier of basement tanking, structural waterproofing, and damp proofing systems. As a Newton-approved installer, Garratt’s has continuous access to the company’s market-leading range of products and training, giving them the confidence and technical knowledge to tackle even the most complex of projects.
The end result was the creation of a dry, ventilated space that was fully refurbished and is now an active part of the tenant’s business. Both the tenant business owner and the building owner have the reassurance that the basement space has been waterproofed to meet the British Standards BS 8102.
Should there be a ‘failure’ in the system installed by Garratt’s, BS8102 stands in as a legally recognised code of practice. To this end, Garratt’s ensures that the products it uses, and the level of workmanship it maintains and expects from all its employees, adhere to these regulations.
The building owner has the reassurance that his property’s never-ending flooding issues have been permanently resolved, which means that both the building will be protected and maintained to a higher standard, and the tenant has access to all the space available within the lease.
The tenant is happy because his business is protected against the danger of any further flooding, and they can concentrate on building the business using the extra space available.
If you have any damp proofing, waterproofing, or basement tanking needs, contact us now to discuss your needs.