5 minute read

Damp Proofing Pricing Guide

Updated and Fact checked: 18-01-22

Average – £300

Range – £250 – £600

Lowest price – £250

Most homes in the UK experience dampness at some point. It’s mainly attributed to the high amount of rainfall the country experiences in a year. However, a build-up can lead to health issues. For this reason, it is imperative to get rid of any moisture to inhibit the effects of dampness.

This guide outlines the requisite measures to ensure your home is damp-free. We shall also discuss the types of damps, their causes, the ways of solving them, the cost of proofing a damp surface, materials used, and additional charges.

How much does damp proofing cost?

The costs vary depending on the type of damp and the solutions applied. Therefore, arriving at an estimated value on the overall process of damp proofing your home becomes a challenge.

Damp proofing cost	Average price
Damp proofing external walls amount	£750 – £2,500
Damp proofing course	£250 – £1,500
Damp proofing per metre	£50 – £75
Damp proofing cellar/basement – tanking	£30 – £60 per sqm
Chimney damp proof course(excluding scaffolding and labour)	£75 per roll
Injection damp proofing	£1,000 – £5,000
Chemical damp proofing	£750 – £3,000

Types of damp and their respective solutions.

Before you embark on the repairs, it’s essential to identify the type of damp in your house to establish the appropriate solution.

Rising damp

It occurs when groundwater sips into your house from beneath. It’s detected by inspecting your home exterior to identify a horizontal rising seal, typically 6-inches above the ground. It then spreads through the foundation into the walls and fans across the floor. A damp proofing course will prevent this dampness.

Damp proofing course (DPC)

Also known as remedial damp proofing, it’s structured to act as a protective barrier for moisture rising through capillary action. On an average property, it can cost up to £800.

It’s vital to have this barrier made when building a house to prevent:

Plaster, wallpaper and paint deterioration.
Reduced wall durability.
Aggressive mould stains.
Floor damage.

Additionally, it’s prudent to hire a tradesperson as they possess the capacity to repair or install the DPC. The tradie will inspect the site and advice on the most appropriate technique to inhibit the build-up of the damp. The type of DPC to be used is dependent on the extent of damage to the walls and floors.

Types of damp proofing course

Mortar Injection – Used in homes prone to voids and have more internal rubble. It’s directly caulked into the site. The cost ranges from £50 and £60 for a 20kg bag.
Liquid or cream injections – The process entails drilling holes into the walls for the application to be successful and effective. You can also do a DIY with an aerosol can, which costs £17 for 310ml and covers about 1.6m.
Electroosmotic course – This method uses a scientific way to reverse the capillary’s polarity by using titanium or copper to create an electric charge that prevents water from rising.
Damp-proofing rods – This is another DIY solution that costs £20 for a pack of 10 rods and will cover 1.2m wall length. You insert the rods into the predrilled holes and release the liquid chemical through the mortar course.
Damp metre- It works by measuring the conductivity of the brickwork between two points and calculates the amount of damp. Unfortunately, it does not prove if you have rising damp but rather informs you of the presence of damp which needs further investigation. Again, a DIY version is available and goes for about £20 to £150.

The table below shows the average price and labour for the different houses requiring a damp proofing cost.

Type of house	Estimated cost
Detached house	£1,500 – £2,000
Semi-detached house	£500 – £800
Terraced house	£280 – £370
Labour costs	£150 – £300

Damp course cost calculator

Depending on the extent of damage, below are some factors that influence the cost of repair.

The extent of damage on internal or external walls.

The external wall damage will be costlier to repair than the internal wall. For every damaged wall that’s treated, you may spend £75 per metre. An average house will require approximately £450 for digging the soil and laying the gravel. However, if you plan to apply a concrete path, it will cost £2,000 and higher.

Independent damp survey

You might have experienced a musty smell in your home but couldn’t pinpoint the exact location. Fortunately, you can hire an independent surveyor to conduct a probe and formulate a report. This will cost you around £150 – £200. The good news is that the surveyor will have saved you money on extraneous procedures of locating the damp.

Type of damp proofing

The cost of treatment varies with the type of damp.

The extent of damage

You may fail to detect the dampness earlier, most likely due to its location. However, if the damage is extensive, the cost of treatment will increase.

Condensation

This type of damp is prevalent and mainly occurs in areas with high amounts of humidity, like the kitchen and bathrooms. It usually happens when water vapour falls on cold surfaces, making them wet. The moisture, therefore, penetrates the walls, ceilings and floors. If left unattended, over time, it moulds.

One can reduce condensation in a room by; taking all wet clothes outside rather than having them dry inside the house and using an extractor fan to reduce the level of moisture in the air. You can also invest in a dehumidifier to control and lower humidity. The average cost will be around £50 – £200.

Penetrating damp

It mostly occurs after moisture seeps into your walls through spaces like cracks and holes. If not earlier detected, it can lead to mould and dampness. You can apply the following methods to prevent the damp from penetrating further into your house;

Replace damaged windows.
For damaged renders – Cracked renders allow water or moisture to pass through. Use a sealant or entirely replace the render.
For damaged gutters or pipes- This is one of the major causes of penetrating damp and is fixed by unblocking or replacing the pipes and gutters.
For roof/ceiling damage – You can opt to have the whole ceiling replaced. If it’s a leaking ceiling, you should fill it up using plaster or drywall mud or entirely replace the roof bricks.
For porous bricks – It’s common for older buildings to experience penetrating damp because of aged or damaged bricks. Replacing them would be ideal.

There are different types of materials used when damp proofing a house. They include:

Continuous plastic sheets under floors.
Semi-rigid materials like mastic asphalt.
Mortar with waterproofing compounds.
Rigid materials like slate, stone, cement concrete painted with bitumen or cement mortar.

Professional VS DIY

A professional guarantees excellent quality and increases the longevity of your property. In addition, they are well versed with the chemicals and equipment used and the different techniques of dealing with the damp.

However, a DIYer can also undertake some tasks which require minimum experience and tools. For example: