Our Technical Consultant, Paul Callaghan was approached by Kings of Essex to give assistance on a particularly technically complicated project.  Kings of Essex have previously worked with Paul on waterproofing projects and knew Paul would be able to furnish them with a waterproofing solution which could be incorporated in this complex waterproofing challenge.

The project in question was a new build luxury property in North London, providing almost 17,000 sq ft of accommodation, set over four floors.  This spectacular mansion is refined in luxury with marbled flooring, atrium hallway, several bedrooms, a home cinema, luxury spa, swimming pool, massage, nail bar and hair dressing salon, entertaining rooms, formal and informal dining rooms.

High volumes of hydrostatic water pressure was bearing on the structure, which was causing the property to suffer severe water ingress through construction joints.

The property when constructed was built at a low level, it sits lower than the neighbouring properties adding to the hydrostatic water pressure issue.  An additional problem was the property had been built without a waterbar/hydrophilic strip.   A waterbar or hydrophilic strip will expand when a structure experiences water ingress, slowing down/stopping water ingress.  It is good building practice to incorporate a waterbar/hydrophilic strip to any below ground structure.

The property when built incorporated a cavity drain membrane system (not Delta’s) and sump pump units.

The rooms to the basement considered of: swimming pool area, spa, massage, nail bar and hair dressing salon, comms room, electrical intake room and maids quarters.

The electrical intake room was exceptionally flooded which raised a health and safety issues for the occupiers of the property, leading Kings of Essex needing to take immediate remedial action.


The project, due to its size and complexity was set into phases.

The first phase was to ensure the property was made safe from electrical dangers.

The second phase was to stop the water ingress.  Once the structure had been stripped back to its concrete core, the water ingress to construction joints was addressed.

A waterbar/hydrophillip strip cannot be retrofitted, meaning this project could not allow for installation.  Paul recommended using the Koster brand of concrete repair solutions to limit and slow down the water ingress experienced.

Paul’s first recommendation was to use Koster KD 2 Blitz – waterstop to the construction joints.  Koster KD Blitz Waterstop, stops active water ingress and safely seals off pressurized water from the negative side. Koster KD 2 Blitz is highly reactive with an extremely short setting time (active water leakages are sealed within seconds).

Once the construction joints were sealed Paul suggested applications of Koster NB1 and Koster Repair Motar Plus.  KD Blitz was added as a secondary line of defence with NB1 coated to external walls throughout the basement structure to stop any water ingress (“locking down the structure”).

Consideration was given to managing future water ingress issues. Paul suggested adding additional sump pump stations throughout the structure.  Paul met with Delta’s partner company PPS (Package Pump Systems Limited) on site to explore options.

Delta’s MS20 offered a perfect solution to the floor design, with its 20mm stud it is ideally equipped to deal with the volume of water ingress.  The next phase of the project is for installation of the same.

Case Study Results

Les King and Peter Colella of Kings of Essex were overjoyed with Paul’s understanding and no nonsense approach.

Paul’s on site attendance and eye for detail were exactly what was needed for this project.  Paul created a waterproofing system which would allow for the issues caused by the hydrostatic water ingress to be addressed.

By incorporating Paul’s waterproofing solutions, water ingress was nullified.

The Delta Membrane System will be installed within the next 6 weeks and we look forward to revisiting this project as it evolves.

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