Looking to understand the cost of basement tanking? Our comprehensive guide details the factors, methods, and additional costs. Prevent damp-related damage today.
What Is Basement Tanking?
Basement tanking is a waterproofing method that prevents water from entering a basement or cellar. It involves applying a waterproof coating or membrane to walls and floors to stop moisture penetration. This process is essential for properties in areas prone to dampness or flooding.
There are two main types of basement tanking: internal and external. Internal tanking involves applying waterproof slurry or membranes to the inside of the walls, while external tanking protects the outer structure of the basement.
Both methods help create a dry and usable space, whether for storage, living areas, or commercial use. Proper basement tanking improves structural integrity and prevents damp-related issues such as mould, rot, and damage to belongings.
Factors That Affect the Cost of Basement Tanking

The cost of basement tanking depends on several factors, including the size of the basement, the condition of the existing structure, and the chosen waterproofing method. Larger basements require more materials and labour, increasing overall expenses.
The type of tanking system also affects pricing. Internal slurry-based tanking is often more affordable than external membrane solutions, which require excavation.
The severity of existing damp or water damage can also impact costs, as repairs may be needed before tanking can begin. Additionally, labour costs vary depending on location and the expertise of the contractor.
A professional assessment is recommended to determine the most suitable approach and estimate expenses accurately.
Types of Basement Tanking and Their Costs
There are three main types of basement tanking, each with different costs:
Cementitious Tanking: This involves applying a waterproof slurry to internal walls and costs between £40 and £80 per square metre. It is a popular option for minor damp problems.
Membrane Tanking: A plastic membrane is fitted to walls and floors, allowing water to drain safely. This method costs between £50 and £100 per square metre and is often used in severe damp conditions.
External Tanking: This method involves applying waterproof materials to the outside of the basement walls. It is the most expensive option, typically costing between £100 and £200 per square metre due to the excavation work required.
The total cost will depend on the size and condition of the basement, as well as the complexity of the installation.
Additional Costs to Consider
Aside from the main tanking work, additional costs may arise during the project. Structural repairs may be necessary if the basement walls or floors have cracks or damage. Repairing these issues before tanking can add significant costs.

Drainage systems, such as sump pumps or channel drainage, may also be required to manage water effectively. These can cost between £500 and £2,000, depending on the system.
Ventilation and dehumidifiers may be needed to prevent condensation, adding further expenses.
If external tanking is chosen, excavation work can be costly, especially if access is limited. Labour fees, permits, and professional assessments also contribute to the overall budget. Planning for these additional costs helps prevent unexpected expenses during the process.
Is Basement Tanking Worth the Investment?
Basement tanking is a worthwhile investment for homeowners seeking to protect their property from damp, flooding, and structural damage. A properly tanked basement increases a home’s value by creating additional dry and usable space, whether for storage, living areas, or commercial purposes.
While the initial cost can be high, tanking prevents costly repairs caused by water damage and mould. It also improves indoor air quality and protects belongings from damp-related deterioration. For properties in flood-prone or high-moisture areas, basement tanking provides long-term peace of mind.
However, homeowners should consider their budget and the condition of their basement before proceeding. A professional consultation can help determine whether tanking is the best solution and which method suits their needs.
If you're looking for basement tanking systems and services for your home or commercial building, contact Above Water Damp Proofing Ltd. It's essential to protect your property from water damage, structural damage, and harmful mould growth that could be bad for your health.