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Basement Waterproofing London

Keep your London basement permanently dry with a professionally designed, BS 8102-compliant waterproofing system — tanking, cavity drainage or a combination, guaranteed and built to last.

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Is water getting into your basement?

London's Victorian and Georgian basements were never designed to be dry, habitable rooms. Below-ground walls sit against damp soil, and without a functioning waterproofing system water finds its way through the masonry, floor joints and any weak points in the structure.

The result is damp walls, musty smells, ruined finishes and — where basements have been converted — real damage to floors, plaster and belongings. Left unmanaged, persistent water ingress undermines both the usability and the value of the space.

We diagnose exactly where and why water is entering, then design a system that controls it for good.

Signs you need waterproofing

  • Damp patches, tide-marks or salt staining on basement walls
  • Standing water or pooling after heavy rain
  • Musty smells, condensation or black mould
  • Bubbling paint or blown plaster below ground level
  • You're converting a cellar into living space
  • An existing tanking or membrane system has failed

How Our Basement Waterproofing Works

A clear, code-compliant process from first survey to final guarantee.

01

Free survey & diagnosis

A qualified surveyor inspects the basement, identifies the water source and water table conditions, and specifies a compliant system.

02

System design to BS 8102

We design a Type A, Type C or combined waterproofing solution appropriate to the structure and how the space will be used.

03

Professional installation

Our specialist team installs membranes, drainage channels, sump and pump, and any tanking — cleanly and to manufacturer specification.

04

Testing & guarantee

The system is tested and commissioned, and you receive written guarantees on materials and workmanship.

BS 8102 Compliant

Systems designed to the British Standard.

Free Survey

Written report and fixed quotation.

Guaranteed

Workmanship and materials warranty.

Basement Waterproofing FAQs

How much does basement waterproofing cost in London? +
It depends on the size of the basement, the severity of the water problem and the system specified. A cavity drainage membrane installation typically starts in the low thousands; a full waterproofed conversion costs more. We give a fixed written quote after a free survey.
Can you waterproof a basement from the inside? +
Yes. Most London basements are waterproofed internally using a Type C cavity drainage membrane or Type A tanking, because external excavation around a terraced property is often impractical. We assess which approach — or combination — is right for your building.
What is the best waterproofing system for a London basement? +
For a habitable basement in period London stock we usually recommend a Type C cavity drainage system, sometimes combined with tanking. It manages water to a sump and pump rather than relying on a single barrier, which is the most reliable approach under variable water conditions.
Do you offer a guarantee on basement waterproofing? +
Yes. We install manufacturer-approved systems and provide written guarantees on workmanship and materials. The term depends on the system, and we set it out clearly in your quotation.

Basement Waterproofing Across London

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Book a Free Basement Survey

We'll diagnose the water problem and specify the right system — free, in writing, with no obligation.

Get a Free Quote