The cost of basement construction depends on several factors, including the size of the basement, the ground conditions, the intended use of the space, and the waterproofing system required. Every project is unique, so we recommend arranging a professional survey, where one of our experienced surveyors can assess your property and provide a detailed, no-obligation quotation tailored to your requirements.
Waterproof Tanking
Professional Protection Against Basement and Cellar Water Ingress
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Waterproof Tanking London
Protect your basement, cellar or below-ground structure with a professionally designed waterproof tanking system.
Universal Basement Waterproofing provides specialist waterproof tanking for domestic and commercial properties throughout London and the South East.
We investigate damp and water ingress before designing a waterproofing system around the property, its construction and the intended use of the finished space.
Our experienced team installs cementitious barrier systems, cavity drain membranes and combined waterproofing solutions using established products from Delta, KÖSTER and Sika.
Qualifying domestic and commercial installations receive our free 10-year installation and product warranty.
Request Your Waterproof Tanking Survey
or call
020 3795 4900.
Professional Waterproof Tanking in London
Basements, cellars and other below-ground structures are exposed to moisture within the surrounding ground. When the structure is not adequately protected, water can penetrate through walls, floors, joints, cracks and service openings.
Waterproof tanking is used to protect these areas against damp and water ingress. Depending on the building, the solution may resist water at the structure or manage it through a cavity drainage system.
The correct approach depends on the condition of the building, the level of groundwater pressure, the existing drainage and how the internal area will be used.
Our surveyors assess these factors before recommending a waterproof tanking system. This helps avoid installing a product that may not be suitable for the property or the conditions it faces.
When Is Waterproof Tanking Required?
A waterproofing survey may be required if your basement or cellar has damp walls, peeling paint, damaged plaster, visible mould, salt deposits, musty smells or standing water.
Water entering through cracks, walls, floors or wall-to-floor junctions can indicate that the structure has no effective waterproofing or that an existing system has failed.
Waterproof tanking may also be needed when a basement or cellar is being converted into a room that requires a dry internal environment.
New basement construction, retaining walls, plant rooms, lift pits and underground commercial areas also require carefully designed structural waterproofing.
Not every damp patch is caused by groundwater. Condensation, leaking plumbing, defective drainage and external building defects may produce similar symptoms. We investigate the likely source before proposing any tanking work.
Waterproof Tanking Systems
Waterproof tanking can refer to several different methods of protecting a basement or below-ground structure. The most appropriate system must be selected according to the property and its level of risk.
Type A Waterproof Tanking
Type A waterproofing uses a barrier applied to the walls and floor to resist water passing through the structure.
Cementitious coatings, specialist waterproof renders and other bonded materials may be installed directly onto prepared masonry or concrete. The barrier must be continuous across the protected area, including corners, joints and service penetrations.
This approach is often described as traditional tanking because the walls and floor are treated to form a sealed internal structure.
Type C Cavity Drain Protection
A Type C system controls water rather than attempting to block it completely at the internal face of the structure.
Studded cavity drain membranes are installed across the walls and floor. Any water entering through the building is directed behind the membrane towards drainage channels and, where required, a sump and pump system.
This type of waterproofing is frequently used in existing basement and cellar conversions because it can accommodate minor movement and manage water in a controlled way.
Combined Waterproofing Systems
Some properties require more than one form of waterproofing protection. A Type A barrier may be combined with a Type C cavity drainage system to provide additional resilience.
Combined protection may be recommended where the consequences of water entering the completed space would be particularly serious or where the structure faces a greater level of groundwater risk.
Every Waterproofing System Starts With a Survey
There is no universal tanking specification that can safely be applied to every basement. Before recommending a system, our surveyor will inspect the construction and condition of the property.
The survey considers how and where water may be entering, the condition of the walls and floor, the stability of the substrate, construction joints, cracks, service penetrations and existing drainage.
We also consider how the finished room will be used. A basic storage cellar may have different waterproofing requirements from a bedroom, office, cinema room or commercial space.
Following the inspection, we provide a clear recommendation explaining the proposed waterproofing system and the work required to install it.
Our Waterproof Tanking Process
Initial Property Assessment
We discuss the problems affecting the basement or cellar, any history of flooding and your plans for the finished space.
Water Ingress Investigation
Our surveyor inspects the walls, floor, joints, cracks, drainage and any existing waterproofing installation to identify the likely water entry routes.
Waterproofing Design
We select a Type A, Type C or combined system based on the construction, substrate, groundwater risk and required internal environment.
Detailed Scope of Work
You will receive a clear specification and quotation explaining the preparation, waterproofing installation and associated work.
Preparation of the Structure
Existing finishes may need to be removed so the substrate can be inspected and prepared. Defective masonry, cracks, joints and penetrations are treated before the main waterproofing system is installed.
Professional Installation
Our trained technicians install the selected system in accordance with the waterproofing design and the relevant manufacturer’s requirements.
Inspection and Documentation
The completed system is inspected and documented before final finishes are installed.
Warranty and Ongoing Protection
Qualifying waterproofing installations receive our free 10-year installation and product warranty. Optional insurance-backed warranty protection is also available.
Why Correct Preparation Matters
A waterproof tanking system can only perform correctly if the underlying structure is properly prepared and all vulnerable details are addressed.
For Type A cementitious tanking, paint, plaster, loose render, salts and contaminated material may need to be removed. The waterproof coating must bond to a stable and suitably prepared masonry or concrete surface.
Cracks, damaged mortar, corners, floor junctions and service penetrations must be treated as part of the complete system. If one area is left unprotected, water pressure may find a route around the new barrier.
Type C systems also require careful planning. The membranes, sealed joints, perimeter drainage, inspection points and any sump pumps must work together to safely manage water.
Our technicians prepare and install the complete system rather than applying a waterproof product only to the visible damp area.
Established Waterproof Tanking Products
Universal Basement Waterproofing installs professional products from recognised waterproofing manufacturers.
As Delta Membrane Systems approved installers, we provide cavity drain membranes, drainage components and associated Type C waterproofing systems.
We also install KÖSTER waterproofing products, including specialist mineral and cementitious systems for masonry and concrete structures.
Sika waterproofing systems may also be specified where they are appropriate for the structure and the required form of protection.
The product manufacturer alone does not determine whether a waterproofing installation will succeed. The design, preparation, detailing and standard of installation are equally important.
Domestic and Commercial Waterproof Tanking
Residential Basements
We waterproof existing and newly constructed residential basements, whether the area will be used for storage or converted into a high-quality living space.
Cellars
Damp and water-affected cellars can be surveyed, waterproofed and refurbished to create dry, protected and more useful areas.
Period Properties
Older London properties often contain irregular masonry, historic alterations and limited external access. These factors must be considered when selecting an appropriate waterproof tanking system.
Commercial Basements
We undertake waterproofing for offices, shops, apartment buildings, storage areas and other commercial premises.
Plant Rooms and Service Areas
Below-ground plant rooms and service spaces may require waterproofing to protect equipment and reduce the risk of disruption caused by water ingress.
Lift Pits and Retaining Structures
We provide waterproofing recommendations for lift pits, retaining walls, vaults and other concrete or masonry structures exposed to water pressure.
New Basement Construction
Our surveyors can assist with waterproofing design during the planning and construction of new below-ground structures.
Waterproofing a Basement for Conversion
A basement conversion needs more than a visually dry finish. The waterproofing system must be designed to protect the completed room against the expected level of water ingress.
Depending on the property and relevant permissions, a waterproofed basement may become a home office, gym, cinema room, playroom, utility space, storage room or additional living accommodation.
The intended use of the room influences the required waterproofing performance. An occupied room containing valuable finishes and electrical equipment will require a higher level of protection than an unfinished storage area.
Universal Basement Waterproofing can complete the project from stripping the area back to the substrate and installing the waterproofing through to the full refurbishment of the space.
Repairs to Failed Waterproof Tanking
If an existing tanking system is leaking, the reason for the failure must be established before repairs begin.
Failures may be associated with inadequate surface preparation, structural movement, cracks, incomplete detailing, damaged membranes, blocked drainage or pump problems.
Our surveyors inspect the original installation and assess whether a targeted repair is appropriate or whether the system requires more extensive replacement.
Simply covering the visible leak may cause the water to move to another part of the structure. Any remedial design should consider the complete waterproofing system and the pressure acting against it.
Why Choose Universal Basement Waterproofing?
More Than 50 Years of Experience
Our team combines specialist waterproofing knowledge with extensive construction and property refurbishment experience.
Delta Approved Installation
We are approved installers of Delta Membrane Systems and install professional cavity drainage solutions.
BS 8102-Compliant Recommendations
Our waterproofing recommendations follow the principles of BS 8102 for protecting below-ground structures against water ingress.
Multiple Waterproofing Options
We install Type A barrier systems, Type C cavity drainage and combined waterproofing solutions according to the needs of the property.
Domestic and Commercial Experience
Our work ranges from residential cellars and basement conversions to large commercial waterproofing projects.
Complete Project Delivery
We can manage the survey, waterproofing design, installation, documentation and complete internal refurbishment.
Documented and Guaranteed Work
Qualifying installations receive our free 10-year installation and product warranty, with optional insurance-backed protection available.
Waterproof Tanking Across London and the South East
We provide waterproof tanking throughout London, Kent, Surrey, Essex, Sussex and surrounding areas.
Our team works with homeowners, landlords, developers, contractors, commercial property owners and facilities managers.
If you are unsure whether we cover your location, call our waterproofing team on 020 3795 4900.
Waterproof Tanking Frequently Asked Questions
What is waterproof tanking?
Waterproof tanking is the installation of a system designed to protect walls and floors against water ingress. It commonly refers to a bonded Type A waterproof barrier but may also be used more generally when discussing basement tanking and cavity drainage.
Does waterproof tanking stop all damp?
Tanking is designed to protect against water passing through a structure. It will not resolve condensation, plumbing leaks or unrelated external defects. The source of the damp should be identified before a system is specified.
Can you waterproof an existing cellar?
Yes. Existing cellars can usually be waterproofed using cementitious tanking, a cavity drain membrane or a combined system. The most appropriate method depends on the property and the level of water ingress risk.
Can tanking be installed over plaster?
Type A cementitious tanking normally needs to bond directly to suitable masonry or concrete. Existing plaster, paint and loose finishes will generally need to be removed. Type C membranes also require the structure to be assessed before installation.
Is a cavity drain membrane better than tanking?
Neither system is automatically better. Barrier tanking resists water, while a cavity drain membrane manages and redirects it. The correct approach depends on the condition of the structure, expected movement and groundwater pressure.
Can you repair failed waterproof tanking?
Yes, depending on the type and condition of the installation. We will inspect the system and determine whether a localised repair, additional protection or complete replacement is required.
How much does waterproof tanking cost?
The cost depends on the size and condition of the area, the preparation required, the water pressure and the selected system. We provide a detailed quotation following a professional survey.
How long does waterproof tanking take?
Smaller installations may take several days, while larger or more complex projects can take several weeks. The expected schedule will be provided once the design and complete scope of work have been established.
Does waterproof tanking come with a guarantee?
Qualifying domestic and commercial installations receive our free 10-year installation and product warranty. We will explain the applicable guarantee before the work begins.
Do I need a survey before tanking work?
Yes. A professional survey is essential to investigate the water ingress, assess the structure and determine which waterproofing system is appropriate.
Request Your Waterproof Tanking Survey
If your basement or cellar is affected by damp, leaks or water ingress, arrange an assessment with Universal Basement Waterproofing.
Our surveyor will inspect the property, investigate the likely source of the problem and recommend a waterproofing system designed for the structure and its intended use.
You will receive a clear scope of work and a detailed, no-obligation quotation.
Request Your Waterproof Tanking Survey Today
To speak to our waterproofing team, call
020 3795 4900.
Email:
info@unbw.co.uk
Book Your Basement Survey Now
One of our waterproofing specialists will inspect your basement, discuss the most suitable waterproofing system and provide expert recommendations with no obligation.
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Frequently Asked Questions
In many cases, basement waterproofing alone does not require planning permission. However, basement construction, excavation, or significant structural alterations may require planning approval and Building Regulations compliance, particularly in certain London boroughs or conservation areas. We can advise you during your survey and help you understand any permissions your project may require.
The duration of a basement waterproofing project depends on the size and complexity of the work. Smaller waterproofing installations can often be completed within a few days, while larger basement construction or full structural waterproofing projects may take several weeks. Following your survey, we’ll provide a clear project schedule so you know exactly what to expect.
There is no single waterproofing system that is suitable for every property. The most effective solution depends on factors such as the construction of the building, ground conditions, water ingress risk, and how you intend to use the basement. Our experienced surveyors will assess your property and recommend the most appropriate BS8102-compliant waterproofing system, whether that’s a Type A (barrier protection), Type C (cavity drain membrane), or a combined system for maximum protection. We only install proven products from leading manufacturers, including Delta, KÖSTER, and Sika.
Yes. We install high-quality waterproofing systems from leading manufacturers such as Delta, KÖSTER, and Sika, following BS8102 standards for below-ground waterproofing. Our waterproofing systems are fully guaranteed, giving you confidence that your basement will remain dry and protected for years to come. We’ll explain the guarantees available during your survey.
We provide basement construction and structural waterproofing services throughout London, Kent, Surrey, Essex, Sussex, and the surrounding areas. If you’re unsure whether we cover your location, simply get in touch and our team will be happy to help.
Yes. We regularly waterproof existing basements, cellars, and vaults, whether they’re affected by damp, water ingress, or you’re planning to convert the space into a dry, usable room. Every property is different, so we carry out a professional survey to identify the cause of the problem before recommending the most suitable waterproofing solution. Our systems are designed to provide long-term protection while complying with BS8102 standards for below-ground structures.
With over 50 years of experience, Universal Basement Waterproofing has designed and installed waterproofing systems for properties across London and the South East. Our experienced surveyors design BS8102-compliant waterproofing solutions using trusted systems from Delta, KÖSTER, and Sika. From initial survey through to installation, we focus on delivering long-lasting, fully guaranteed waterproofing solutions tailored to every property.
We aim to arrange surveys as quickly as possible, subject to availability. During your survey, one of our experienced waterproofing specialists will assess your basement, discuss your requirements, identify any issues with damp or water ingress, and recommend the most suitable waterproofing solution. You’ll then receive a detailed, no-obligation quotation for the work required.