Crystal Waterproofing Renovations

Coverage · Westminster, Mayfair, Knightsbridge, Belgravia, Marylebone, Pimlico, Kensington and Chelsea

Basement waterproofing in Central London.

Central London is the hardest place in the country to get a basement right, and not because of the ground. The ground is mostly London Clay, which is well understood. It is everything around the ground that complicates the work: listed fabric you cannot touch, party walls on both sides, a street you cannot close, and a council that wants the waterproofing strategy before it will look at the application.

PCA Property Care Association Member firm
CSSW Certified Surveyor in Structural Waterproofing Design to BS 8102
IBG Insurance-Backed Guarantees Available on completed works

The ground across central London

What you are building into.

Ground, groundwater and planning across Central London
GeologyLondon Clay, with river terrace gravels along the Thames corridor
GroundwaterBuried rivers dominate. The Fleet, the Tyburn, the Westbourne and Counter's Creek all still run in culverts beneath these boroughs, and properties sitting on those alignments behave nothing like the street behind them.
Housing stockGeorgian and Victorian townhouses, stucco terraces and mansion blocks, a high proportion listed or in conservation areas
PlanningThis is the most tightly regulated basement market in the country. Kensington & Chelsea and Westminster between them approved the majority of London's basement schemes through the boom years, and both now apply restrictive policy — RBKC caps how far a basement may extend beneath a garden, and Westminster expects a structural methodology statement and construction management plan. The waterproofing design has to exist at application stage, because it forms part of what is being assessed.

We design to BS 8102 with the planning position in mind from the first visit. In practice that usually means Type C drained protection, because it is maintainable and because it does not depend on a perfect bond to historic brickwork that has already been repointed three times. Where a property is listed, the specification has to achieve a habitable Grade 3 environment without altering fabric that is protected — which is a design problem as much as a construction one.

8 areas

Find your area.

Each area below has its own notes on the geology, the groundwater and the housing stock, because the right specification genuinely changes from one postcode to the next.

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Book a survey across central London.

Tell us what you're seeing and we'll tell you honestly whether it needs a full waterproofing system or something much simpler.

Office 4D Heathhurst Road, South Croydon, CR2 0BA

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