Cost of Damp Proofing a Wall

Last updated 20th February 2024 - Reading time: 18 mins
At a glance
  • The average cost of damp proofing a home is around £1,000
  • The job will take approximately 2 - 7 days to complete
In this article, you'll discover the following:
  • A complete pricing breakdown which includes things you need to consider, along with what such a task usually involves
  • How long the job should approximately take and a general overview of what types of services can be performed
  • How to find and hire a damp proofing specialist

Damp and rot can cause extensive property damage if it is left untreated, so it is essential that you recognise it and treat it immediately.

In this guide, we'll cover everything you need to know, including the different types of damp proofing options available to you and what a damp proofer cost is likely to be. On average, you can expect to pay around £1,000 to resolve your issues.

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So, how much does wall damp proofing cost?

damp proofing

Average Cost of Wall Damp Proofing:

Depending on the complexity of the job, it usually takes: 2-7 days


How Much Does It Cost to Damp Proof a Wall?

So how much does damp proofing cost on average? Well this can vary quite drastically depending on the size of your property and the method of damp proofing.

Damp proofing is an umbrella term used to describe all methods and treatments for preventing damp from being absorbed through your walls or floors and into the interior parts of your property.

The average cost to damp proof an average-sized property is around £250-£2000. However, there may be some additional costs that you may also need to think about, such as re-plastering or re-rendering. These additional jobs could increase the overall cost of the work by a substantial amount.

In this article, we'll look at the different types of damp proofing and all of the costs involved with the work.

We will also take a look at the additional costs that could come up, the cost affecting factors that you may need to think about, and some things that you should consider when finding the right contractors for the job.

What are the different methods of damp proofing and which is the best for a Victorian brick built terraced house?

"Damp proof injection , also plastic membrane and dry lining"

Wall Damp Proofing Prices

Below is a table highlighting the different costs involved with damp proofing a home:

Type of work Average cost
Damp proofing cost (per metre) £50-£75
Damp proof course cost £250-£2000
Damp proofing on external walls cost £750-£2500
Damp proof injection cost £1000-£5000
Chemical damp proofing cost £750-£3000
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The overall price you pay will depend largely on the size of the area that you are damp proofing.

The prices above are the average prices for damp proofing alone and do not include any of the following:

  • Damp proofing survey costs
  • Removal of plasterboard or render costs
  • Painting and decorating costs
  • Drying out or dehumidifying costs

Based on these factors, the average cost for damp proofing in the UK is around £850.

The table below indicates the different prices for damp proofing work on various sizes of homes:

Type of work Average cost
Damp proof course – Terraced house £280-£370
Damp proof course – Semi-detached house £500-£800
Damp proof course – Detached house £1500-£2000
Tanking slurry – Terraced house £2450-£3500
Tanking slurry – Semi-detached house £2800-£3800
Tanking slurry – Detached house £4560-£6000
Re-plaster – Terraced house £1200-£1800
Re-plaster – Semi-detached house £1800-£2400
Re-plaster – Detached house £2400-£3000
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Supply Only Costs

Below is a table highlighting the different costs for supplies when it comes to damp proofing a home in the UK:

Type of Supply Average Cost
Damp meter £20-£150
Injected DPC £500-£2000
DPC cream £9-£15 per metre
DPC rods £15-£20 per metre
Mortar injection DPC £50-£60 per bag of mortar
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The supplies you need will depend on the type of damp proofing work you are having done and the size of the area being worked on. In most cases, the contractor will provide all of the materials needed for you, and they will incorporate those costs into the overall price of the job.

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Additional Costs

When it comes to damp proofing your home, there are some additional costs that you may need to consider. Below is a list of the additional costs that may come with this type of work:

Extractor Fan

In areas such as the kitchen or bathroom where the room is prone to becoming damp, it may be good to invest in a good extractor fan to help release some of the damp and prevent it from building up in the room. The average cost for an extractor fan is around £150-£250.

extractor fan


If your home is prone to dampness, a dehumidifier is one of the best investments you can make. These machines are designed to extract and collect moisture from the air. They then release the clean, dry air back into the room. This is great for preventing damp but also great for your health. The average cost for a dehumidifier is around £70-£100.

Leaking Roof Repair

If you find that the cause of damp in your home is a leaking roof, you will need to get this repaired quickly. The price you pay for this type of work will depend on the extent of the leak and the type of leak. The average cost to repair a leaking roof is around £50-£100 per m2.

Replacement Gutters

Sometimes, the cause of damp is due to leaking or faulty guttering. If this is the case, then you may need to invest in some new gutters. The average cost for replacement gutters is around £480-£720, depending on the size of your home.

replacing gutters

Window and Door Resealing

You can further prevent damp from becoming an issue by having your doors and windows resealed. The average cost for this type of work is around £50-£60 per window and £80-£100 per door.

New Doors

If the doors in your home are quite old, then it may be a good idea to get some new doors to ensure they are fully sealed and can prevent dampness from becoming an issue. The average cost for new doors is around £50-£1500 per door.

New Windows

Similarly, you may also want to replace your old windows with new ones as these will be much more efficient and much better at preventing damp from becoming a big issue. The average cost for new windows is around £200-£350 per window.


Damp proofing your home will often make quite a mess of the walls, and you will often need to get these re-plastered. The average cost for plastering the walls is around £400-£700 per room.



When you get an external damp proof course, you may need to get your home rendered afterwards. The average cost of rendering a home is around £4000-£8000, depending on the type of render and the size of your home.

Painting and Decorating

As we have mentioned earlier, damp proofing a home can make a real mess of the walls. With this in mind, you'll likely need to re-decorate once the work is complete. The average cost to have your home painted or wallpapered is around £200-£400 per room

Labour Costs and Timescales

A professional damp proofing contractor will usually charge a daily fee of around £100-£200. This will depend on their level of expertise and your location in the UK. Those based in the London area can expect to pay more for the labour part of the job than those based in the North or other parts of the UK.

The time it takes to complete the work will depend on a range of factors, including the size of your home, the size of the area being worked on, the extent of the job, and the ease of access to the worksite. Damp proofing will usually take around 2-7 days to complete.

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Cost Factors of Damp Proofing a Wall

Several factors can affect the price you will pay for damp proofing your home. Below is a list of the main cost affecting factors that you may need to be aware of with this type of work:

Severity of Problem

The longer the damp has been left untreated, the worse the damage will be. If the damp has been ignored or simply covered up, you may find a lot of hidden damage that you weren't aware of.

Once your contractor has completed a survey, they may uncover more problems than you realised. If there is extensive damp damage, this can affect the structural integrity of your home and will, therefore, require more work.

damp wall

If the damage is small, the work tends to be quite simple, and the damp effects can be reversed by drying out the affected area. With this in mind, the worse the problem is, the more you can expect to pay.

Type of Treatment

There are several different types of damp proofing treatments, and the type you need will depend on the type and severity of the damp problem in your home. Some issues can be quite simple to fix, and others may require more extensive work.

Treatments that take a longer amount of time to complete will incur higher labour costs that can really add up depending on the length of the job.

Size of the Treatment Area

Depending on the cause of the damp in your home, it may be limited to just one small area. In these cases, the work won't take anywhere near as long as some other jobs, so you will end up paying much less.

For more severe cases where the damp has spread through several rooms, this will take much longer to complete and will end up costing much more.

damp proofing wall

What's Involved in Wall Damp Proofing?

There are a few different ways in which you can damp proof your home. Below is a list of the various methods and what each method entails:

Damp Proof Course

The following steps will be taken to install a new damp proof course:

  1. Drill holes in the wall measuring 12mm in diameter at intervals of 115mm and at least 150mm above the ground.
  2. Inject the damp proof course starting from the bottom until it is full.
  3. Fill each hole with plastic plugs or cap them with mortar to prevent leaks.

Tanking Slurry

A professional tanking slurry involves these steps:

  1. Plaster, paint and other debris need to be removed from the wall surfaces and then cleaned.
  2. A salt neutraliser will then be added to the wall to prevent existing salts from affecting the tanking.
  3. While the wall is slightly damp, holes are filled with mortar, cement, sand, and a waterproof element.
  4. The wall then needs to be dampened again before applying the tanking slurry. It should be applied with a soft paste brush horizontally.
  5. It then needs to be left for 24 hours to dry before another coat is added.

Damp Proof Paint

To damp proof your home with damp proof paint, the following steps will be taken:

  1. Any damp plaster will be removed, and all loose fixtures will be secured.
  2. The wall will then be cleaned with all existing paint removed.
  3. The first coat of damp proof paint will be applied using spray or a brush.
  4. While the paint is still wet, dried kiln sand will be added to smooth out the surface.
  5. The second layer of paint will then be added.

The walls will be re-plastered once the paint is dry.

Can I Damp Proof a Wall Myself?

Damp proofing can often be quite extensive work, and it's important to carry it out correctly to ensure that the damp is fully taken care of and won't return. With this in mind, it's a good idea to leave this type of work up to a professional damp proofer. Some types of damp proofing, if done incorrectly, can cause damage to your home.

cleaning mould

Many of the DIY damp proofing options involve hiding the damp rather than actually treating the cause. If you choose to hide your damp with one of these treatments, it will end up costing you more in the long run as the damp will only get worse over time.

There are some aspects of the work that can be done as a DIY job. For example, you could save some money by re-decorating the rooms yourself rather than hiring a professional for this part of the job. This could save you around £300-£400 per room.

Building Regulations & Planning Permission for Damp Proofing

Any work involving damp proofing is usually classed under permitted development. However, if your damp proofing is part of a larger project, you may need planning permission. Projects that typically need planning permission are:

  • Altering the external appearance of the property
  • Changing the use of an existing basement
  • Creating a new basement

If your property is a listed building or in a conservation area, you will likely need to apply for planning permission for damp proofing. If you're not sure whether you will need planning permission or not, it's best to get in touch with your local authority for some advice.

When it comes to damp proofing the walls, you must adhere to some building regulations rules. The rules state that your damp proof course should:

  • Join up with any damp proof membrane or damp proof course on the flooring
  • Be a minimum of 1.5cm above the ground if the work is on an external wall
  • Be a minimum of 2.25cm above the bottom of a cavity unless a cavity tray is installed

Types of Damp Proofing

There are several different types of damp proofing jobs. Here are some details on each of the different damp proofing methods:

Damp Proof Course

A damp proof course (DPC) is a type of damp proofing installed in a property to prevent damp problems from occurring.

These are usually installed on new properties during the building phase as it is a regulation now that all properties must have a damp proof course for health and safety reasons. There are various methods of installing a damp proof course. The most common process is a damp proof injection.

This type of treatment involves injecting a damp proof cream made up of a silicone-based liquid into the walls. This liquid reacts with the silica in the masonry to produce a waterproofing layer within the wall that prevents dampness from entering the home.

Tanking Slurry

A tanking slurry is quite a big job as it involves removing all of the plaster, paint, and wallpaper from the wall surface before the work is completed.

A salt neutraliser is then typically applied to the wall to prevent existing salts in the wall from affecting the tanking slurry.

The wall is then slightly dampened, and holes are filled with cement, mortar, and a waterproofer. The wall is then dampened again before applying a tanking slurry. This is typically left for around 24 hours before another coat is added. Once the second coat is completely dry, the wall should then be re-plastered and decorated once

removing plaster


If your walls need to be re-plastered, a layer of PVA glue should be applied first to allow the plaster to dry out evenly. While the glue is still slightly wet and sticky, the plaster will be mixed and applied to the wall.

When the first coat of plaster has been applied, it should be left for 20 minutes before it is skimmed and smoothed out to get rid of any bumps. After that, a second coat can be added, but this will be a much thinner coat than the first.

To finish off the plastering job, water will be applied to the surface to smooth out any bumps that may still be present. Sanding paper will then be used to smooth out and remove any excess plaster.

After the plastering work is completed, the wall can then be re-decorated.

Benefits of Damp Proofing

There are many benefits to damp proofing your home. Below is a list of the advantages of this type of work:

Improve The Appearance of Your Home

Dampness in the home can cause unpleasant dark patches on your walls that can look very unsightly. It can also cause your wallpaper to wilt and peel and can cause paintwork to crack.

Damp-proofing your home will prevent this from happening, and you can decorate your home freely without the worry of any damp-related appearance issues.

new kitchen

Avoid Reducing the Value of Your Home

Many people choose to cover up the damp in their home rather than getting it treated properly. However, unless you get your damp problems treated professionally, they will keep coming back and could get much worse over time, causing a lot of damage to your home.

The sight of damp may prevent future buyers from wanting to buy your house. If you damp proof your home professionally, you can avoid this issue.

Prevent Health Issues

Several health issues can occur due to dampness in the home. Mould and mildew thrive in damp conditions, and mould can cause various health issues, including coughing, wheeziness, headaches, throat and eye irritations.

Damp-proofing your home will eliminate any potential damp-related health issues and will help to keep you and your family safe.

Avoid Unpleasant Smells

Damp problems in the home can lead to unpleasant smells, especially when there is a significant amount of mould. If left untreated, the smell of mould and damp can become overwhelming.

By using a damp treatment process, this will eliminate all odours of damp from within your home.

unpleasant smell

Prevent Structural Problems

Leaving a damp area untreated can cause damage to the timbers in the structure of your property. Dampness can cause the wood in your structural timbers to rot, and they can even potentially collapse.

Choosing to damp proof your home can prevent any chances of rotting from occurring and helps to keep your property safe and secure.

Hiring Contractors to Damp Proof a Wall Checklist

You will need to consider a few things before hiring contractors to damp proof your home for you.

Below is a list of some of the main things that you should consider when looking for the right contractors for the job:

  • Does the contractor offer any guarantees with their work?
  • How much is the work to complete? – Ask for a breakdown of costs so you can ensure you are paying a good price for each element of the job.
  • Is the contractor experienced in installing the type of damp proofing that you are looking for?
  • How many years' worth of experience does the contractor have in damp proofing homes?
  • How many contractors will carry out the job?
  • Will the contractor fix any issues that may arise?
  • Will the contractor take care of any relevant waste removal?
  • Do you need to hire any additional contractors for different parts of the work?
  • Will the contractor follow all of the relevant building regulation guidelines?


Can you damp proof basement walls?

The method for damp proofing a basement is a tanking slurry. A tanking slurry involves stripping away the walls until they are bare and then applying the slurry to the bare walls before plastering and decorating them. This will make the structure of the basement complete watertight.

What is the best damp proof treatment for internal walls?

The best damp proof treatment for internal walls is usually a damp proof course that involves creating various holes in the wall and filling them with a damp proofing cream before re-plastering and decorating the walls.

What causes dampness on internal walls?

Damp is typically caused by a build-up of moisture on the surface of the walls of your home. It can occur more commonly in areas where moisture is present more often, such as in the kitchen or bathroom.

Is rising damp covered on my home insurance?

In the majority of cases, rising damp is not covered on home insurance. However, every insurance policy is different, so you should double-check your particular policy just to be sure.

Is it true that damp can cause health issues?

Yes, leaving damp untreated can lead to several health issues, including coughing, wheezing, congestion, and an irritated throat or eyes. It can also cause some chronic health issues such as reduced lung function or asthma if you live in a home with damp for long periods.
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