How Much Does Damp Proofing Cost?

Dampness can leave unsightly spots on your walls, affect your building’s structure, and leave a musty smell behind; that’s why damp proofing is a necessary step to protect your house. But how much does damp proofing cost?

The exact price depends on the type of damp proofing you choose, the extent of damage in your house, and many other factors. To save you the hassle of asking around, we’ll answer your question in detail in this article.

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Damp Proofing in a Nutshell

Damp proofing means protecting the walls of your property from moisture creeping up inside them and causing irreversible damage.

You can damp proof your walls by adding a protective layer between them and the moist source, adding a waterproof material to the concrete mix, or spraying them with water-repellent materials. There are also many other methods, but these are the most famous.

Damp proofing is necessary because if moisture reaches inside your walls, it can make your paint crumble, promote the growth of termites, and cause efflorescence on your bricks. All of these effects will eventually lead to weak spots in your house’s structure.

Moisture can also increase the risk of short circuits if the water reaches your electrical fittings. Another point you should consider is that it can significantly affect your house’s overall appearance and smell.

If you wait too long without damp proofing your wall, you risk irreversible damage and expensive fixes.

Causes of Dampness and How They Affect the Cost of Damp Proofing

Knowing what causes dampness in your house is essential so that you know how to fix it. Here’s a quick list of the possible reasons why moisture might be showing up on your walls.

  1. Leaking pipes: Rusty or holey downpipes, corroded or damaged water pipes
  2. Low-quality or faulty construction material: Water penetrates low-quality and defective construction materials by capillary action
  3. Groundwater: It might rise from the ground up the foundation walls through capillary action
  4. Rainwater: When rain splashes on the exterior walls of your house, it might penetrate them till it reaches your inner wall and cause damp spots

The cost of proofing your walls will partially depend on the reason behind the moisture, but why? Well, before damp proofing, you’ll need to fix the existing damage. For instance, low-quality construction materials are expensive to replace. Meanwhile, leaky pipes don’t cost much if the damage isn’t too extensive.

While groundwater has easy fixes, they often require a large budget. As for the rainwater issue, it’s often easy and affordable to fix.

How Much Does Damp Proofing Cost for a Wall?

The average cost of damp proofing a wall in your house ranges from £300 to £400. However, it can go anywhere from £300 to £5000 for the whole house, depending on your walls’ size, the type of damp proofing, and the damage.

Also, it might differ slightly according to where you live in the United Kingdom. Generally, populous cities like London have higher labour prices than less crowded ones.

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Damp Proofing: Types and Their Different Costs

Here’s a breakdown of the most common damp proofing types and their costs.

Damp Proof Injection

This method involves the injection of a damp proof material made from a silicone-based liquid into the wall. The injection forms a water-repellent layer between the wall and the moisture source, providing protection and minimising moisture damage.

The cost of injecting your walls is about £70 per metre, which rounds to £250-300 for each wall. Of course, you can save money by purchasing damp proofing materials and injecting the walls yourself, but leaving matters to professionals is always better.

Tanking Slurry

This solution is for severe dampness cases, so you might not need to opt for it. It involves applying a thick coating material to walls so that it acts as a barrier against water. It’s a preferred method for many as it prevents rot and mould. As for its cost, it ranges from £30 to £60 per square metre.

Membrane Damp Proof Course

This method involves placing a waterproof membrane, usually made from polyethene, under a concrete slab to prevent moisture from passing through the concrete. It costs about £100-130 per square metre and is easy to install.

Electro-Osmosis Damp Proofing

This method depends on stopping water from rising up your wall with the help of an electric charge. The electric charge is supplied through embedded wires into your walls, and they send moisture back towards the ground.

Despite the effectiveness of this course, it isn’t widely used because installing wires in your walls is complicated, and the process can be costly. It costs about £250-300 per 25 metres.

What Factors Affect the Final Cost of Damp Proofing?

The final cost of damp proofing your walls depends on many factors. Here’s a roundup of the most important ones.

Type of Dampness

There are three types of dampness that might reach your walls, rising dampness, condensation, and penetrating dampness.


Condensation is the most common type in the United Kingdom, and it happens when warm and damp air condenses on cold walls. It’s a common issue in rooms with high percentages of air moisture, like kitchens and bathrooms. This issue has many easy and affordable fixes, like letting more air enter the rooms.

Penetration Dampness

Penetration dampness is caused by the leakage of water through your walls. It’s often a result of structural problems like cracks in ceilings or leaking gutters. Unfortunately, it can expand quickly to surrounding walls and ceilings, making it a challenging and pricey issue.

Rising Dampness

Rising dampness is the priciest issue to fix, and it occurs when dampness rises up your walls through capillary action, often causing extensive damage to paint and plaster. It can also cause structural issues and weaken your walls, which is why it costs more than the other two types to fix.

Size and Number of Walls

As you’ve seen above, most prices are per square metre, which means the larger your walls are, the more money you’ll have to pay. The number of walls is also a factor. For instance, if you’re damp proofing the walls of one room in your house, you won’t dent your wallet. But if you’re damp proofing the entire building, you might need to set aside a large budget.

The Extent of Damp Damage

If the moisture reaches deep into your walls and causes structural problems, fixing the issue and damp proofing will cost much more than if the damage is still manageable. That’s why it’s essential to keep an eye out for damp spots on your walls and fix them once they happen.

Type of Damp Proofing

Each damp proofing method has a different cost. For example, tanking slurry costs less than damp proof injections, and they both cost less than electro-osmosis damp proofing. So the final cost will depend on the type you choose.

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An Affordable Approach to Damp Proofing

A more affordable approach to damp proofing is to tackle the smaller projects yourself. For instance, if you have leaky gutters, you can fix them without the help of a professional. The same goes for leaky pipes if they don’t need replacements.

Also, if you choose an easy damp proofing method, like injection, you can try to do it yourself. You’ll only need to pay the price of the injecting material, and that’s it. But it’s fair to warn you that you should leave it to an expert if you aren’t confident enough in your skills. Faulty damp proofing methods can cost you large amounts of money to fix.

Calculating Damp Proofing Costs

To calculate damp proofing costs, you’ll need to settle on a damp proofing type. The choice should depend on the cause of your problem.

For example, if groundwater is the culprit, then you should try electro-osmosis damp proofing or any other solution that deals with water coming from the ground. Alternatively, if your problem is rainwater, you can try a membrane damp proof course to prevent the splashing moisture from penetrating your concrete.

After settling on a type, you should measure the walls and see how many square metres you’ll need to damp proof. Then, multiply the metres by the cost of the damp proofing method per metre.

Finally, check the labour costs in your city as they differ from one place to another.

If you fail to determine the reason for your problem or can’t choose between the different damp proofing methods, it’s best to consult a professional and then calculate the costs. You can also use an online damp proofing cost calculator.


Damp proofing is necessary if your building is susceptible to condensation, penetration dampness, and rising dampness. It can prevent moisture from reaching inside your walls and protect your building from structural damage.

The cost of damp proofing your house can go anywhere from £300 to £2500. But the final price depends on the extent of the damage and the type of proofing you choose.

If you decide to damp proof your place, contact us now!

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