Specialist Tanking and Waterproofing Works to Transform a Previously Failed Basement
At Crown Preservation, we specialise in resolving complex waterproofing problems where previous repair attempts have failed to provide a lasting solution.
One recent project involved a privately owned property in Mayfair, London, where four interconnected underground vaults were suffering from persistent water ingress.
The vaults had previously been treated by another contractor, but the waterproofing works had failed to resolve the problem. Crown Preservation was brought in to investigate the cause of the leaks and develop a long-term solution.
The project required a combination of specialist resin injection, structural repairs and a comprehensive tanking system to fully protect the underground spaces from further water ingress.
The Problem
The four interconnected underground vaults were affected by significant water penetration, with moisture entering through the masonry and around structural junctions.
Previous attempts to resolve the leaks had been unsuccessful, leaving the vaults vulnerable to continued water ingress and further deterioration.
One particularly problematic area was around a steel beam above a doorway, where running water could be seen seeping through the surrounding masonry.
It was clear that simply treating the visible water damage would not be enough. The underlying cracks, gaps and weaknesses within the structure needed to be properly addressed before the waterproofing system could be installed.
Preparing the Vaults for Waterproofing
Before the tanking system could be applied, the surfaces needed to be thoroughly prepared.
The existing render had been removed by the client’s builder following Crown Preservation’s instructions. Our team then sandblasted the walls and ceilings to remove foreign materials and loose debris, creating a clean and suitable surface for the waterproofing system.
The masonry was subsequently washed down using high-pressure water to ensure the surfaces were free from grit and other loose material.
This preparation was an essential part of the process, ensuring the tanking system could properly bond with the underlying structure.
Repairing Structural Weaknesses and Water Pathways
The vaults contained numerous internal corners and wall-to-floor junctions, as well as holes and other defects within the masonry.
Crown Preservation carefully repaired these areas using specialist repair mortar, including the application of strengthening fillets to the internal 90-degree junctions.
Particular attention was given to the leaking steel beam above the doorway.
A groove was cut into the masonry where the steel met the surrounding structure, allowing injection packers to be installed. Specialist resin was then pumped into the structure, displacing water and penetrating the cracks and gaps.
Once the resin had sealed the internal water pathways, the groove was repaired using a flexible seal.
This ensured that the underlying source of the leak was properly addressed before the main tanking system was installed.
Installing the Specialist Tanking System
With the structural defects repaired, Crown Preservation applied a specialist waterproof slurry system to the masonry.
Koster NB1 was applied using high-pressure spray equipment, allowing the material to penetrate deeply into cracks and cavities within the masonry.
The application process also helped identify further defects that required attention. Any additional cracks, holes or weaknesses were repaired before a second coat of waterproof slurry was applied.
A further layer of NB1 Elastic slurry was then installed, with five coats applied to provide a flexible and durable waterproofing barrier.
The elastic nature of the system allows it to accommodate movement within the structure, helping to reduce the risk of cracking and future waterproofing failure.
Creating a High-Quality Finished Space
Once the waterproofing system had been completed, multiple coats of specialist lime render were applied over the tanking system.
The hydrophobic render provides an additional level of water resistance whilst creating a suitable surface for the final finish.
At the client’s request, the lime render was then skimmed with multi-finish plaster to create a clean, high-quality appearance.
The result was not simply a dry and waterproofed structure, but a significantly improved underground space with a professional finished appearance.
The Finished Result
The four interconnected vaults were successfully waterproofed following the previous failed repair attempts.
By addressing the underlying structural defects, sealing hidden water pathways with resin injection and installing a comprehensive flexible tanking system, Crown Preservation was able to provide a long-term solution to the persistent water ingress.
The vaults were repaired, protected and given a complete makeover, transforming previously problematic underground spaces into clean, dry and usable areas.
The works are covered by a lengthy Crown Preservation guarantee, together with an insurance-backed GPI guarantee.
Project Highlights
- Four interconnected underground vaults in Mayfair, London.
- Persistent water ingress following unsuccessful previous repairs.
- Specialist investigation to identify the sources of water penetration.
- Structural cracks, holes and defects repaired using specialist repair mortar.
- Resin injection used to seal water pathways around a leaking steel beam.
- Specialist Koster NB1 waterproof slurry system installed.
- Five coats of flexible NB1 Elastic slurry applied.
- Specialist hydrophobic lime render installed over the tanking system.
- Final multi-finish plaster applied at the client’s request.
- Long-term waterproofing protection provided with guarantees.
Why Crown Preservation?
At Crown Preservation, we understand that successful basement waterproofing requires more than simply applying a waterproof coating.
Every structure is different, and persistent water ingress can often be caused by hidden cracks, structural junctions and pathways within the masonry. Our experienced team takes the time to investigate the underlying problem before designing a solution specifically for the building.
With over 30 years of experience in damp proofing, basement waterproofing and property preservation, we have the expertise to tackle challenging projects where previous solutions have failed.
Whether we are working on a prestigious Mayfair property, a historic building or a domestic basement, our approach remains the same: identify the cause, solve the problem properly and provide long-lasting protection.
Crown Preservation – Preserving the Past, Protecting the Future.
If you are experiencing persistent water ingress, damp or a leaking basement or vault, call us on 0207 412 8267 and we would be happy to talk through your requirements.
