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.
Cellar Tanking
Guaranteed Cellar Waterproofing for a Dry, Protected and Usable Space
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Cellar Tanking London
Every installation is completed to recognised industry standards and supported by our free 10-year installation and product warranty.
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Professional Cellar Tanking in London
Cellars and basements are particularly vulnerable to damp and water ingress because their walls and floors are situated below ground level. Moisture may penetrate through the structure due to hydrostatic pressure, defects in the existing waterproofing, cracks, leaking drainage or changes in the surrounding ground conditions.
Simply covering visible damp will not provide lasting protection. The cause of the problem must first be identified before the correct cellar waterproofing system can be designed.
Our surveyors inspect the property, assess the level and source of water ingress and determine how the cellar will be used. We then provide a clear specification for a waterproofing system designed around the building and the risks identified.
More than 50 years of building and waterproofing experience
Delta Membrane Systems approved installers
BS 8102-compliant waterproofing designs
Free 10-year installation and product warranty
Solutions using Delta, KÖSTER and Sika systems
Domestic and commercial cellar waterproofing
Complete waterproofing and refurbishment available
Signs Your Cellar May Need Tanking or Waterproofing
You should arrange a professional cellar survey if you have noticed any of the following:
Damp or wet cellar walls
Water entering through walls, floors or wall-to-floor joints
Peeling paint, damaged plaster or crumbling surfaces
Black mould, mildew or musty smells
White salt deposits on walls or floors
Puddles or flooding after heavy rainfall
High humidity or condensation
Rotting timber or damage to stored belongings
An existing tanking system that has failed
Water ingress rarely resolves itself. Left untreated, it can continue to damage finishes, stored belongings and parts of the building. An early professional assessment can identify the cause and help prevent the problem from becoming more extensive.
Which Cellar Tanking System Is Right for Your Property?
There is no single waterproofing system suitable for every cellar. The correct approach depends on the construction of the property, the level of water pressure, the condition of the existing structure and how you intend to use the finished space.
Our surveyor may recommend one of the following systems or a combined waterproofing solution.
Type A Barrier Protection
Type A waterproofing uses a continuous waterproof barrier applied directly to the cellar walls and floor. This is often referred to as cellar tanking. Specialist cementitious coatings or waterproof renders are used to resist water passing through the structure.
Type C Cavity Drain Membrane
A Type C system uses a studded cavity drain membrane installed across the internal walls and floor. Any water entering through the structure is controlled behind the membrane and directed towards a suitable drainage point or sump and pump system.
Type C systems are frequently used when converting existing cellars because they manage water ingress while providing a dry internal surface that can be finished to create a usable room.
Combined Waterproofing Systems
Properties with a higher risk of water ingress may require more than one form of waterproofing protection. Where appropriate, we can design a combined system to provide additional resilience and protection.
All recommended systems are designed around the findings of the survey and installed using proven products from manufacturers including Delta, KÖSTER and Sika.
Our Cellar Tanking Process
1. Professional Cellar Survey
One of our experienced surveyors will inspect your cellar, discuss the problems you are experiencing and learn how you intend to use the space.
2. Identify the Cause of Water Ingress
We assess the cellar walls, floor, joints, drainage and surrounding conditions to identify where moisture is entering and the level of future risk.
3. Design the Waterproofing Solution
We recommend a cellar tanking or cavity drainage system tailored to the property, your intended use and your available budget.
4. Provide a Clear Scope of Work
You will receive a detailed recommendation and quotation setting out the proposed system and the work required.
5. Install the Waterproofing System
Our trained technicians prepare the substrate and install the specified waterproofing system in accordance with the relevant manufacturer’s requirements.
6. Testing, Documentation and Guarantee
The completed work is inspected and documented. Qualifying commercial and domestic waterproofing installations receive our free 10-year installation and product warranty.
Turn a Damp Cellar Into Valuable Usable Space
Once correctly waterproofed, an unused cellar can become a valuable part of your property. Depending on its size, layout, ventilation and regulatory requirements, the space could potentially be transformed into:
A home office
A cinema or entertainment room
A gym or wellbeing room
A playroom
A utility or laundry room
A wine cellar
A storage room
Additional living accommodation
Universal Basement Waterproofing can provide a complete one-stop service, from stripping the cellar back to the substrate and installing the waterproofing system through to the full refurbishment of the finished space.
We undertake projects ranging from smaller domestic cellar conversions to complex commercial waterproofing works and projects valued at more than £1 million.
Why Choose Universal Basement Waterproofing?
Cellar tanking is only effective when the system is correctly designed, the surfaces are properly prepared and every component is installed to the required standard. Our team combines specialist waterproofing knowledge with extensive construction and refurbishment experience.
Over 50 years of construction and waterproofing experience
Delta Membrane Systems approved installers
Experienced waterproofing surveyors and technicians
BS 8102-compliant waterproofing recommendations
Detailed survey reports and clear specifications
Installation using recognised waterproofing manufacturers
Technical support throughout the project
Complete waterproofing and refurbishment service
Free 10-year installation and product warranty
Optional insurance-backed warranty protection
We do not simply cover over visible damp. We identify the cause, design the right waterproofing system and install it to provide lasting protection.
Cellar Tanking Across London and the South East
We provide cellar tanking, cavity drain membrane installation and structural waterproofing services throughout London, Kent, Surrey, Essex, Sussex and surrounding areas.
Our team works on Victorian and period properties, modern homes, commercial buildings, plant rooms, vaults, new basement constructions and existing cellar conversions.
If you are unsure whether we cover your area, call our team on 020 3795 4900.
Cellar Tanking Frequently Asked Questions
What is cellar tanking?
Cellar tanking is a method of waterproofing the internal walls and floor of a below-ground room. A waterproof barrier is installed to prevent moisture and water from passing into the finished internal space. The term is also commonly used more generally when referring to cellar waterproofing.
Is cellar tanking the same as a cavity drain membrane?
No. Traditional tanking is normally a Type A barrier system that attempts to resist water passing through the structure. A Type C cavity drain membrane system manages water entering the structure and directs it safely to drainage or a sump and pump. The right system depends on the property and the level of water ingress risk.
Can you tank an existing cellar?
Yes. Existing cellars can usually be waterproofed, whether they are affected by damp, occasional water ingress or persistent flooding. A survey is required to determine the construction and condition of the cellar before recommending the correct solution.
How much does cellar tanking cost?
The cost depends on the size and condition of the cellar, the extent of the water ingress, the amount of preparation required and the waterproofing system selected. Following a professional survey, we will provide a detailed quotation based on your property.
How long does cellar tanking take?
Smaller waterproofing installations may be completed within several days, while larger or more complex projects can take several weeks. We will provide an expected schedule after surveying the property and confirming the required work.
Will cellar tanking stop damp permanently?
A professionally designed and correctly installed waterproofing system can provide long-term protection. Its effectiveness depends on selecting the right system, preparing the structure correctly and allowing for drainage and maintenance where required.
Does cellar waterproofing come with a guarantee?
Yes. Universal Basement Waterproofing provides a free 10-year installation and product warranty upon completion of qualifying commercial and domestic waterproofing work. Optional insurance-backed warranty protection is also available.
Do I need planning permission to waterproof my cellar?
Waterproofing an existing cellar will not normally require planning permission when no significant structural or external changes are involved. However, excavation, structural alterations, a change of use or work to a listed property may require permission or Building Regulations approval. We can discuss this with you during the survey.
Arrange Your Cellar Waterproofing Survey
If your cellar is damp, leaking or currently unusable, arrange an assessment with one of our waterproofing specialists.
We will inspect the property, identify the likely cause of the problem and recommend a cellar tanking or waterproofing system designed for your building.
Professional cellar assessment
Clear waterproofing recommendation
Detailed, no-obligation quotation
Guaranteed installation
Request Your Cellar Tanking Survey Today
Prefer to speak to someone? Call a waterproofing specialist on
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.