Approved member of the Federation of Damp
Below-ground waterproofing specialists · Wimbledon, SW19
Basement Waterproofing in Wimbledon
Wimbledon has two very different kinds of ground: the hill around the Village and the Common, and the low ground of the Wandle valley towards South Wimbledon. Advanced Damp designs and installs basement waterproofing across SW19 for both, from Edwardian cellars to new basements under large family homes.
Newton Approved
Below-ground waterproofing across London and the South East.
CSSW and CSRT Trained Surveyors
Systems designed and specified to BS 8102:2022.
Long-Term Guarantee
Written guarantee on all new waterproofing installations.
CHAS Accredited
Fully insured, fixed-price quotations after survey.
Hill, Valley and Spring Water
Wimbledon Village and the Common sit on a plateau of sand and gravel over London Clay. As on other London hills, rain soaks into the sand and gravel and comes out at the clay boundary on the slopes. The streets running down Wimbledon Hill and the roads around the Ridgway sit on that slope, and houses built into it often have water pressing on the rear walls of their cellars and lower ground floors after wet weather.
At the bottom of the hill the ground changes. Towards Wimbledon town centre, South Wimbledon and Colliers Wood, the land falls into the valley of the River Wandle, where river gravels and alluvium carry a higher water table. Basements here deal with groundwater that sits close to the floor level for much of the year rather than water arriving from the hillside.
Wimbledon's housing is mainly large Victorian and Edwardian family houses, with older properties in the Village and a growing number of modern homes and rebuilds. Many of the older houses have cellars under part of the ground floor, and Wimbledon has seen a steady number of basement extensions under houses and gardens as owners look for extra space without building upwards.
Because the ground changes so much across SW19, we do not use a standard specification. A house near the Common may need protection against seasonal spring water, while a house near the Wandle may need a pumped system designed for a permanently high water table. The survey decides which applies.
Wimbledon is in the London Borough of Merton, and much of the Village is in a conservation area. New basements need planning permission, structural design and drainage information, and often a party wall agreement. We design waterproofing to BS 8102 and work with your architect and engineer.
Why Wimbledon Basements Need It
Wimbledon basements face spring water on the hill and a high water table in the Wandle valley. Common local risk factors include:
Left untreated, this sustained moisture pressure leads to efflorescence and salt staining, plaster breakdown, mould growth, timber decay in ground-floor joists and, over time, structural deterioration of the masonry itself.
Our Waterproofing Systems
Wimbledon basements see both seasonal spring water on the hill and a high water table in the valley. We specify systems that collect and remove that water rather than simply coating over it. A survey decides which system is right for your property.
Type A · Cementitious Tanking
A rigid bonded coating applied directly to sound masonry. Suited to Wimbledon cellars with stable brickwork and lower moisture risk storage spaces, plant rooms and vaults where full habitable conversion is not required.
Basement tanking →Type C · Cavity Drain Membrane
Our most specified system for SW19. A studded membrane channels groundwater safely to a sump rather than resisting it. the reliable choice where sustained hydrostatic pressure makes blocking water impractical.
Cavity drain membrane →For new basement excavations or projects requiring Camden planning submissions, see our work on structural waterproofing and cellar tanking.
How We Work
Groundwater & Assessment
A CSSW surveyor visits your Wimbledon property, identifies the water source, and reviews any previous failed treatments before recommending a system.
System Design & Fixed Price
We specify the right system for SW19's groundwater conditions to BS 8102:2022 and provide a clear, fixed-price proposal agreed before any work begins.
Installation & Guarantee
Our own teams install the system, no subcontracting. On completion, we issue a written long-term guarantee and advise on long-term sump maintenance.
Why Choose Advanced Damp in Wimbledon?
What Our Customers Say
"Sam and Jack were excellent. Before starting the work they outlined exactly what was to be done and kept us informed throughout. Professional, tidy and delivered great results."
Christian Morrison, Google Reviews"We called Advanced Damp after noticing a musty smell in our living room. They did a damp survey and explained everything really clearly. Really glad we went with them, great service."
George Freeman, Google ReviewsPlanning work on a basement in Wimbledon?
The right system depends on how water reaches your walls and floor. A survey finds that first, so the design fits your property and the price is fixed before anything starts.
Book a Basement SurveyCall 0300 373 7251- 1. Book online or callPick a time that suits you.
- 2. Surveyor visitsMoisture readings, water source and the condition of the walls and floor.
- 3. Written specificationThe right system for your basement, with a fixed price and no obligation.
A Real London Type C Project
Basement Waterproofing Project in Fulham
See how our team successfully designed and installed a complete basement waterproofing system for a residential property in Fulham. This project highlights our risk-led approach, high-quality workmanship, and long-term waterproofing solutions for London homes.
Basement Waterproofing Across London
We design and install basement waterproofing across London and Surrey. Choose your area for local ground conditions, common problems and FAQs.
Accredited & Trusted
Recent Basement Work Near Wimbledon
Our recent basement waterproofing work includes lower ground flat, Wandsworth SW18; new basement, Fulham SW6 and basement flat entrance, SE20. Each case study sets out what the survey found and how the problem was fixed.
Lower ground flat, Wandsworth SW18
Bedroom mould from condensation and groundwater. Type C waterproofing, smart fans and a mould wash.
Read the case study →
New basement, Fulham SW6
A Type C cavity drain membrane system installed to a newly built lower ground floor, designed to BS 8102:2022 for a Grade 3 dry, habitable space.
Read the case study →
Basement flat entrance, SE20
A blistered wall inside the front door was rising damp in one small area, treated with a DPC and tanked render.
Read the case study →Wimbledon Basement Waterproofing FAQs
Why do basements on Wimbledon Hill get wet when the house is high up?
The top of the hill is sand and gravel over clay. Rain soaks in and comes out where the sand meets the clay on the slopes, so houses part way down the hill can have water pressing on their walls even though they are well above the valley floor.
Do basements near South Wimbledon need a different system?
Often, yes. Near the River Wandle the water table is higher and steadier, so the basement may sit in water for much of the year. These basements usually need a cavity drain system with a pumped sump and a backup pump, designed for constant rather than seasonal water.
Can you waterproof a basement under a new extension in Wimbledon?
Yes. For new basements we work with your engineer at the design stage so the concrete structure and the waterproofing work together. BS 8102 recommends combined protection for habitable basements in wet ground, and that is usually what we specify in Wimbledon.
How long does the waterproofing guarantee last?
Every new installation comes with a long-term written guarantee. The exact terms depend on the system and the work carried out, and we set them out in writing with your specification before work begins.
Do I need to tell my neighbours before waterproofing my basement?
Waterproofing an existing basement from the inside does not normally need a party wall notice. Digging a new basement, lowering the floor or underpinning near a shared wall does. Your surveyor or architect can advise on the notices needed.
Do you cover Raynes Park, Southfields and Morden?
Yes. We cover Wimbledon, Wimbledon Village, South Wimbledon, Raynes Park, Southfields, Colliers Wood and the surrounding SW19 and SW20 streets.
Related Services
Book a Wimbledon Basement Waterproofing Survey
If your Wimbledon property has a cellar or basement showing damp, salts or water, or you are planning a new basement, the first step is a survey by a CSSW and CSRT trained specialist who knows how the ground changes across SW19.
We will assess your specific building, identify the source and type of water ingress, and specify the right system in writing with a fixed price.