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 · NW8
Basement waterproofing in St John's Wood.
St John's Wood is one of the few parts of inner London built as detached and semi-detached villas rather than terraces, and the plots are correspondingly generous. That makes basement work more straightforward in one respect — there is often genuine external access — and no easier in another, because the Tyburn runs down through the area from the Hampstead ridge on its way south.
Ground conditions
What sits beneath St John's Wood.
| Postcodes | NW8 |
|---|---|
| Geology | London Clay |
| Groundwater | Moderate; the Tyburn descends from the Hampstead ridge through this area |
| Housing stock | Detached and semi-detached villas on generous plots, mansion blocks |
Detached plots frequently allow an external drainage solution alongside the internal system, which is worth establishing at survey because it can change the specification substantially.
St John's Wood is one of the areas we cover across North London.
Specification
Choosing the right system for St John's Wood.
BS 8102 sets out three forms of protection. Which one suits a property in St John's Wood 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.
Request a quote
Book a survey in St John's Wood.
Tell us what you're seeing and we'll tell you honestly whether it needs a full waterproofing system or something much simpler.