The True Cost Of Tanking A Cellar Or Basement In The UK

Tanking a cellar, which involves applying a waterproof coating to the interior walls and floor to prevent water ingress, is a popular method for converting damp, unused basements into habitable spaces. However, the cost of this process can vary widely based on several factors. In this article, we’ll explore what tanking a cellar or basement entails, the factors influencing its cost, and provide a general idea of the expenses you might incur.

What is Tanking?

Tanking is a term used to describe the process of making walls and floors watertight. It typically involves the application of a waterproof membrane or coating to the interior surfaces of a cellar or basement. The aim is to create a barrier that prevents water from penetrating the walls and floor, effectively protecting the interior space from damp and water damage.

Factors Influencing the Cost of Tanking a Cellar

1. Size of the Cellar

The size of the cellar is one of the most significant factors in determining the cost of tanking. Larger cellars will require more materials and labour, increasing the overall cost.

2. Condition of the Cellar

The current condition of your cellar can greatly affect the cost. If there is significant damage or if extensive preparatory work is needed (such as removing old paint, fixing cracks, or dealing with existing damp issues), this will add to the overall cost.

3. Type of Tanking System

There are various tanking systems available, each with different price points:

• Cementitious Tanking: Involves applying a waterproof cement-based coating. This is usually the most cost-effective option.
• Liquid Membranes: These are applied like paint and form a waterproof layer once dried. They tend to be more expensive than cementitious options but can be more flexible.
• Sheet Membranes: These are physical barriers (like sheets of rubber or plastic) that are applied to the walls and floor. They are often more expensive but can be highly effective.

4. Additional Waterproofing Measures

In some cases, additional waterproofing measures may be needed, such as installing a sump pump or drainage system. These can add to the cost.

5. Interior Finishing

After tanking, you may want to finish the space for habitation, which could include insulation, plastering, flooring, and decoration. These finishing touches will add to the overall cost.

6. Professional Fees

Hiring a professional waterproofing contractor is recommended for tanking, and their fees will be a significant part of the cost. Ensure they are experienced and accredited by relevant bodies such as the Property Care Association (PCA).

Average Costs of Tanking a Cellar

The cost of tanking a cellar in the UK can range from a few thousand pounds to tens of thousands, depending on the size and condition of the cellar and the type of tanking system used. Here are some rough estimates:

1. Cementitious Tanking: Expect to pay around £40 to £70 per square meter.
2. Liquid Membranes: These can cost between £50 to £90 per square meter.
3. Sheet Membranes: Costs can range from £70 to £100 per square meter.

Source: https://www.checkatrade.com/blog/cost-guides/basement-waterproofing-costs/ 

Remember, these are average prices and can vary based on the factors mentioned above. Additional costs for preparatory work, professional fees, and interior finishing should also be considered.

Conclusion

Tanking a cellar can be a substantial investment, but it can also significantly increase the usable space and value of your property. The true cost of tanking a cellar depends on a variety of factors, including the size and condition of the cellar, the type of tanking system used, and any additional waterproofing or finishing work required. It’s crucial to get a detailed assessment and quote from a professional waterproofing contractor to understand the full scope and cost of the project. While tanking can be expensive, the long-term benefits of a dry, usable basement space often outweigh the initial outlay.