Blog>Cost Guides>Damp proofing: Cost breakdown 2025
Last updated: 6 April 2025
Damp proofing: Cost breakdown 2025
The effects of damp on any building can be devastating. However, there are several affordable, easy solutions to deal with this. Damp proofing is an excellent way of not only dealing with damp but also preventing it from occurring in the first place.
Fast Facts
The average cost of retrofitting a damp proof membrane in an average-sized property is around £5,000
Damp can be caused by condensation, penetrating damp, or rising damp
Each problem needs a specific treatment, ranging from improved ventilation to filling cracks and holes, to injection damp proofing
Contact an approved damp proofing specialist for a home assessment
It's wise to tackle damp as soon as possible to prevent costly future problems, including structural damage, mould growth, and even health issues.
The average cost of damp proofing typically sits at around £5,000.
However, there are several types of damp and various solutions to tackle it (and prevent further outbreaks). Read on to discover more about the cost of damp proofing and how to find trusted damp proof companies near you.
How much does damp proofing cost in 2025?
| Damp proofing costs | Cost + VAT (Range low - high) | Average cost |
|---|---|---|
| Damp proofing cost per metre (injection) | £60 - £200 | £100 |
| Damp proofing course (physical damp proof course retrofit) | £2,500 - £7.500 | £5,000 |
| Damp proofing external walls cost (injection) | £1,000 - £3,000 | £2,000 |
| Damp proofing cellar / basement cost - tanking | £100 - £200 per sqm | £125 per sqm |
| Injection damp proofing cost | £1,000 - £3,000 | £2,000 |
| Chemical damp proofing cost | £1,000 - £3,000 | £2,000 |
| Chimney damp proof course (labour and scaffolding not included) | £75 per roll | |
| Damp survey | £100 - £600 | £300 |
| Last updated: November 2024 Our costs are ballpark averages - get a local tradesperson to quote now | ||
There are different types of damp and different solutions to remove and prevent damp. It's therefore difficult to estimate an accurate damp proofing cost for every home.
However, as a guide, expect to pay, on average, around £5,000 for damp proofing.
For the prices in this guide, we have considered the following:
Prices exclude any removal of plasterboard or render
Prices exclude any making good of any plasterboard or render
Prices exclude any decoration or finishes, e.g. skirting boards/floor finishes
Prices exclude any drying out or dehumidification
Prices exclude any survey costs
See the tradespeople we've checked and recommend for your job
Types of damp and related proofing costs
Damp can affect your home in three different forms. Each has the potential to cause damage to walls and can even affect the structural integrity of your property. Types of damp include:
Condensation
This common form of damp usually occurs in bathrooms or kitchens.
Condensation happens when water vapour, for example, from showering, cooking, or drying clothes inside, falls on cold surfaces, making them wet.
The moisture can then sink into walls, ceilings, and even floors causing damp, and if left for too long, mould.
The solution?
The main solution to condensation is through proper ventilation. For example, opening a window, purchasing a dehumidifier, or installing an extractor fan. You could also apply damp proof paint.
As a guide, hiring a qualified electrician to install an extractor fan in a bathroom typically costs around £300
Penetrating damp
Unlike condensation, penetrating damp occurs when moisture from the outside comes into your home through holes in your roof, walls, pipes, doors, windows, and even gutters.
This can then lead to damp, mould, and damage to your home.
On occasion, internal bridging can occur. This is when debris forms a bridge within your wall cavity, giving water an access point to your home.
The solution?
The main fix is to fill or repair the holes - or, in the case of internal bridging, remove the debris - to prevent more moisture from entering your home.
Damp proofing external walls costs around£2,000
In some circumstances, your neighbours' having damp may affect your home. This is especially likely to become an issue when you share a wall. In this case, it is wise to work with your neighbour to find and tackle the cause of the problem.
Rising damp
Rather than coming from outside, rising damp becomes an issue when water from the earth under your home seeps into the foundations, floors, and walls.
This can then cause structural damage, mould, peeling paint, and more.
All homes built after 1875 should have a damp proof course, but even so, it's not immune to wear and tear.
The solution?
Rising damp can be difficult, expensive, and time-consuming to remedy.
There are several types of damp proof course, which act as an essential layer to protect your home from rising damp, including a physical membrane, chemical injections, paints, gels, water-proof plaster, or water-proof cement coatings.
A damp course tends to cost in the region of £2,000 for a medium-sized property, based on injection treatment
Damp proofing prices per project
As we've discovered, damp can occur for several reasons and impact various parts of a property. So let's look at some of the common areas and the average treatment costs.
Damp proofing walls
When it comes to damp proofing walls, there are a number of options. Here's a selection of some of the most common solutions:
Damp proofing external walls
To prevent or deal with penetrating damp, your external walls must be waterproof, with no cracks or holes.
On average, damp proofing external walls costs £2,000
Injection damp proofing
One of the ways to damp proof your home is to inject a waterproof solution between the ground and your home's foundations.
On average, injection damp proofing costs £2,000
Chemical damp proofing
Another form of damp proofing is using chemicals to create a barrier surrounding your home.
On average, chemical damp proofing costs £2,000
Damp proofing chimney stack cost
Out of sight and out of mind, damp in chimneys can be a real problem. If not taken care of it can lead to damp patches on the walls, as well as flaking paint.
While you might be wondering what damp proofing a chimney stack costs, the stack is only one part of the chimney; you’ll likely need to treat the entire chimney from breast to stack to completely remove the issue.
The chimney damp proof course cost you pay will vary depending on the cause of the problem. There are many potential causes, including:
Gaps in external mortar (see our chimney repointing cost guide)
Rising damp
Open chimney pots
Blockages in the chimney
Missing roof tiles
Blocked gutters
Once the root cause has been identified and fixed, you can have a damp proof membrane placed within the chimney or apply a special coating.
A chimney damp proof course typically costs between £75 per roll+ labour andscaffolding costs
Damp proofing a cellar or basement cost
Cellars or basements are often more likely to be affected by damp, and this can go unnoticed for longer than it would be in other rooms in the house.
On average, damp proofing a cellar or basement costs£125 per sqm
Damp proofing cost per metre
It might be possible to ask a damp proof company to give you a damp proofing cost per metre of damage.
The average price for this is typically £100 per metre
Get an accurate quote for the cost of damp proofing your home
Book a trusted local damp proof specialist to visit your home and provide an accurate quote for the damp proofing work required.
Factors affecting damp proofing costs
It is useful when calculating the cost of damp proofing your home to consider the following factors:
Severity of damp
Small patches of damage from condensation are much easier to fix than having to completely install a new damp proof course.
Affected area size
When damp affects a large area, it is likely the issue is more extensive and therefore will be more costly to remedy.
Type of damp and respective treatment
Every type of damp requires a different course of action, some are more expensive than others. For example, rising damp treatments are generally more costly than those for tackling condensation.
Location
The figures in this article should act as a guide only; it's not uncommon to find labour rates higher in London and the South East.
Connect with local damp proof companies who cover your area for an accurate price.
See the tradespeople we've checked and recommend for your job
Hidden costs to consider
The cost of damp proofing can quickly start to add up, so it's good to have a clear idea of what to expect before work commences.
There are one or two costs that might be less obvious to plan for. These include:
Damp survey
A damp survey might be necessary to assess the extent of the damage and to make an informed decision on the best type of treatment. Damp surveys tend to average around £300.
Preventative measures
Once damp has been eradicated from your home, you may wish to purchase a dehumidifier or an extractor fan to prevent future issues.
'Making good'
Following damp proofing treatment, you may need to plaster and paint surfaces to fix any superficial damage.
On Checkatrade, you'll only find trades who meet our high standards and pass up to 12 checks.
Cost of hiring a damp proofing company vs DIY
While there are kits you can purchase to damp proof your home, these are only useful in certain circumstances. Without the help of a professional, there is no guarantee these will work.
In general, whether you can damp proof your home yourself will depend on the type of damp and the cause. For example, condensation can be easily dealt with by adding adequate ventilation.
It can be difficult and time-consuming to eradicate damp from your home, and if this is not done correctly, it can lead to future issues that may be more extensive than your current damp problem.
We always recommend hiring a professional damp proof specialist as soon as possible.
Key takeaways
Damp can have devastating consequences, which will only get worse the longer it is ignored
There are three types of damp: condensation, penetrating, and rising
Damp-proofing your home can be done in several ways, including adding ventilation, filling cracks, and injecting a damp proof solution
Your tradesperson may quote you a damp proofing cost per course, per job, or even per metre
Find a trusted damp proof company near you
View damp proof company profiles, read customer reviews, and contact them directly for quotes and bookings. Download the Checkatrade app or search your postcode below to get started.
See the tradespeople we've checked and recommend for your job
More Cost Guides
See the tradespeople we've checked and recommend for your job