Type A
Barrier protection
Cementitious slurries and spray applied membranes, forming a continuous barrier against the structure. Suitable where the structure is sound and the head of water is modest and well understood.
Hand & spray applied
Areas we cover · SW4, SW11
Basement waterproofing in Clapham.
Clapham is largely London Clay, which makes it one of the more straightforward parts of inner London for below-ground work. That does not make it trivial: the clay is shrinkable, seasonal movement is real, and a rigid barrier system that cracks with the ground has failed regardless of how well it was applied.
Ground conditions
What sits beneath Clapham.
| Postcodes | SW4, SW11 |
|---|---|
| Geology | London Clay, with river terrace deposits to the north |
| Groundwater | Moderate, rising towards Battersea and the Thames |
| Housing stock | Victorian and Edwardian terraces, large villas around the Common |
Clay shrinkage is why we generally favour drained cavity membrane over rigid tanking here — the system tolerates movement instead of fighting it.
Clapham is one of the areas we cover across South London.
Specification
Choosing the right system for Clapham.
BS 8102 sets out three forms of protection. Which one suits a property in Clapham depends on the water head, the condition of the structure and what you intend to use the space for.
Type B
Structurally integral
Water-resistant concrete construction, with joints and service penetrations designed as part of the structure. Usually the route for new basements and underpinned extensions.
New build & underpinned structures
Type C
Drained protection
Cavity drain membrane, perimeter channel and a pumped discharge. It manages water instead of resisting it, and it remains maintainable — which is why it suits most conversions of existing cellars.
Maintainable · Grade 3 habitable
Nearby
We also work in these areas.
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Book a survey in Clapham.
Tell us what you're seeing and we'll tell you honestly whether it needs a full waterproofing system or something much simpler.