Damp Proofing Installation Guide: Types, Residential, Commercial, Prep, and Cost

Damp proofing installation creates a barrier between the walls of your house and the ground. It helps prevent moisture from getting into your house and causing structural damage. 

If you’re experiencing issues with dampness and moisture in your home, then this guide should have you settled. It covers everything from the different types of damp proofing to whether you can DIY this process or leave it to the professionals. 

Damp Proofing Installation Guide in the UK: Types, Prep, Cost, and More

What Are the Different Types of Damp Proofing Installation?

Damp proofing can be installed internally or externally. The choice boils down to the type and extent of dampness you’re dealing with, as well as the building’s structure. 

Fundamentals aside, there are several damp proofing techniques and materials that you can work with, which include: 

Internal Installation

Internal damp proofing is the process of installing a barrier between the ground and the inside of a wall to eliminate rising damp, which is moisture rising from the ground and through the walls. 

This type of damp proofing is often used in interior walls that suffer from moisture originating from within. A good example of such spaces is bedroom or cellar walls.

Internal installation is generally less expensive than external installation. It’s also less disruptive to the household and has little to no effect on the external appearance of the house. 

External Installation

External damp proofing comprises treating moisture originating from the outside (penetrating damp) by applying a protective coating to the external walls of the building.

One example of external installation is applying a waterproof coating to a north-facing exterior wall. This is because north-facing walls don’t get enough sunlight. They’re also more susceptible to wind and rain.

External installation may require scaffolding or other specialist equipment and can be quite noisy. It may require several days or even weeks to complete. 

Installing Damp Proofing to Walls 

Installing damp proofing to walls can be done in a variety of methods, from using a damp proof membrane (DPM) or a damp proof course (DPC) to applying cream or concrete. 

Determining which method is best for your needs depends on the severity of the dampness situation and the type of wall you’re dealing with. When in doubt, consult a qualified damp proofing professional. 

Installing Damp Proof Membrane (DPM)

A damp proof membrane is a waterproof material that you install horizontally within the walls or under the flooring of your home to prevent dampness. 

DPMs are typically made from high-density polyethylene (HDPE), or simply thick plastic. They’re best suited for preventing rising damp.

Installing Damp Proof Course (DPC)

This type of dampness barrier is fitted vertically or horizontally within the walls of a building, often in between the bricks or masonry blocks of the wall. 

DPC comes in a variety of materials. This includes slate, plastic sheeting, and bitumen felt. It’s quite versatile as you can use it to prevent both rising and penetrating damp. 

Installing Damp Proof Plaster

This is a specialty plaster—or render—containing waterproofing additives that prevent water from seeping through the walls and into your house. 

Damp-proofing plaster is intended for interior walls and not the walls outside. 

Installing Damp Proof Paint

Damp-proof paint is a type of paint that contains a waterproofing additive.

To be more specific, it contains a water-reactive agent that prevents residual surface moisture. You can use it on any surface that’s susceptible to dampness, whether it’s inside or outside.

Installing a Damp Proof Sheet

A dampness sheet is a flexible material you lay horizontally below the floorboard to prevent moisture coming from the ground from rising into your place.

Most damp proof sheets are made from rubber or bitumen, and they’re most commonly used in basements and cellars. 

Installing Damp Proof Concrete

Damp proof concrete is what you get when you add waterproofing chemicals to the concrete mix before pouring it. 

The chemicals in the mix work by reducing the size and spacing of the concrete’s capillaries. The result is less porous concrete that can hold its own against water penetration. 

Installing Damp Proof Cream

Dampness cream is a thick, silane-based emulsion that you inject into pre-drilled holes to prevent rising damp. Once in the holes, the cream spreads out to form a continuous moisture barrier. 

This method is perfect for DIY damp proofing projects since it doesn’t require high-pressure injecting equipment. A basic cream applicator with a nozzle will get the job done just fine. 

Installing Damp Proof Injection

This traditional damp proofing process involves injecting a chemical damp proof course (DPC) into walls affected by severe rising damp. 

Though there are similarities between this method and the previous one, they’re not the same. Damp proof injection is more complex and expensive. It also calls for more sophisticated equipment. 

Where Would You Install Damp Proofing?

Now that you have a good idea of the different damp proofing methods, let’s go over a few specific examples that highlight where the installation should take place. 

Residential Properties

There are several places you’d want to damp proof in a residential property. And by residential property, we’re talking about single-family homes, apartments, condos, and other properties zoned specifically for living. 

Examples include:

  • External Walls: If you live in an area with heavy rainfall or flooding, protecting your external walls against dampness is of the utmost importance. This is because water can easily seep into the walls from the ground. The damp proofing should take place at ground level or below. 
  • Internal Walls: The internal walls of areas that are prone to moisture and condensation (e.g., kitchens and bathrooms) should be damp-proofed. Otherwise, these areas will suffer from mould and mildew growth. 
  • Floors: Domestic properties that are prone to leaks or flooding should have damp-proofed floors. This is to prevent water from seeping into the floor from the ground, broken pipes, and whatnot. 
  • Roofs: If your area experiences heavy rainfall or snowfall, you should direct your damp proofing attention to your roof. This is to prevent water from leaking into the roof from the outside and causing structural damage. 

Garage

Garages are often in need of damp proofing because they’re easily exposed to the elements. The external walls and floor of your garage are where you’d want to install the damp proofing. 

The most common method of damp proofing a garage is using a tanking slurry (cementitious tanking). It’s basically a type of waterproof cement that’s fortified with aggregates and polymers. 

We view this method as a sub-category of installing damp proofing concrete. 

Basement

Basements, which are often below ground level, are more susceptible to dampness than most other spaces. That being the case, damp proofing their internal and external walls, as well as their floors, is crucial. 

Commercial Properties

Damp proofing is crucial for the walls (both internal and external) and floors of commercial properties. This includes offices, retail stores, warehouses, medical centers, and so forth. 

Now, bear in mind that different public and commercial buildings have different damp proofing needs. For instance, damp proofing a hotel’s swimming pool differs from damp proofing a warehouse

You see, a swimming pool is constantly exposed to water, both from the inside and the outside. So, naturally, damp proofing it will be more laborious and complex than damp proofing a warehouse. 

Can You DIY Damp Proofing?

Yes, you can DIY damp proofing if you have the necessary skills and knowledge. Just bear in mind that there are varying levels of effectiveness when it comes to DIY property repair and maintenance

You may be able to deal with the situation effectively without the help of a professional if the source of the damp is minor, like a blocked downpipe or a leaking gutter. 

On the other hand, you’ll most likely need the help of a damp proofing specialist if you’re dealing with extreme rising or penetrating damp. 

To put things into perspective, here are the pros and cons of DIY damp proofing:

ProsCons
DIY damp proofing can be more affordable than hiring a professional, especially for minor issues. Damp proofing is a complex process. If you don’t know what you’re doing, you can make things worse. 
You get to deal with the problem on your schedule. You won’t have to wait for a professional to be available. You won’t be as effective with your damp proofing as a professional, especially with serious issues. 
DIY damp proofing can be a learning experience. It can help you gain new handyman skills. Some damp proofing products can be dangerous if not handled properly, like bitumen-based products. 
Completing a DIY repair or maintenance project always brings about a sense of satisfaction. Dampness proofing can be messy and time-consuming, especially when treating a large area. 

How Much Does Damp Proof Installation Cost?

The cost of damp proof installation in a typical UK home ranges from £300 to £4,000 for penetrating dampness and £1,000 to £5,000 for rising dampness. 

Please keep in mind that these price ranges aren’t set in stone and that the cost of damp proof installation can vary based on a wide range of factors, as indicated below. 

Some of the reasons why damp proofing may cost less:

  • The size of the area you’re looking to damp proof is small.
  • The damp proofing technique required isn’t complex.
  • The availability of skilled damp proofers in your area is high.
  • The area you’re looking to damp proof is easy to access.

Some of the reasons why damp proofing may cost more:

  • The damp issue requires special equipment or materials.
  • The project needs to be carried out at short notice.
  • The area to be damp proofed is confined or hard to access.
  • The need to remove and redo existing finishes.

What Preparation Do You Need for Damp Proof Installation?

Preparation for damp proof installation is the process of assessing the source and extent of dampness in the affected area. It also includes clearing the affected surface of any contaminants or debris before work can start. 

Here are the general steps you need to follow to prepare for damp proofing:

  1. Pinpoint the source of dampness. 
  2. Assess the extent of dampness.
  3. Choose a suitable damp proofing product. 
  4. Prepare the surface for damp proofing. 
  5. Take the necessary safety precautions. 
  6. Apply the damp proofing product. 
  7. Inspect the installation to ensure its success. 

Keep in mind that the steps may vary based on several factors such as the type of installation or the type of product. For instance, some products will be applied as a liquid, while others will be applied as a membrane or sheet. 

You also need to factor in the condition of the surface you’re going to work on. Some surfaces may require clearing, repairing, or priming before you start the installation. 

What Are Some Causes of Dampness?

Knowing the cause of dampness in your property is the first step to treating the problem. Having said that, different types of dampness have different causes. 

To clarify, the causes of rising damp differ from those of penetrating damp. And let’s not forget about condensation and its causes. 

Causes of rising damp:

  • Lack of Damp Proof Course: Ideally, buildings are constructed with a waterproofing barrier (DPC) that’s erected from the ground and into the walls. If your building was constructed without any DPC, it’s going to experience rising damp issues. 
  • Failed Damp Proof Course: If your property has a DPC barrier that has failed over time, dampness can travel past it and enter your space. This is likely to happen if your property has intersecting masonry or if there are internal or external renders overlapping the DPC barrier. 

Causes of penetrating damp:

  • Gutters and Downpipes: Penetrating damp is often the result of blocked or overflowing gutters. Broken downpipes may also be a culprit, as they tend to deposit excess water onto external walls. 
  • Construction Issues: Several construction issues may allow water to get into a building’s substrate and cause penetrating damp. Among these issues are missing roof tiles, wall cracks, poorly installed windows, and holes in the roof. 
  • High Groundwater Level: In some areas, groundwater levels can get higher over time. This may put the low-level substrate under pressure, resulting in penetrating damp. 
  • Plumbing Problems: Another common cause of penetrating damp—as well as wet rot—is inefficient or faulty plumbing. Examples include leaky pipes, blocked drains, and faulty toilet bases. 

Causes of condensation:

  • Poor Ventilation: Good airflow is the key to reducing moisture-carrying air. Poor ventilation traps the warm air inside, allowing it to deposit moisture on cold surfaces like external walls and windows. This is why your windows appear foggy when it’s cold outside. 
  • Excessive Moisture: Unfortunately, everyday activities that require high temperatures can contribute to the overall moisture level inside a house. Such activities include cooking, drying clothes, and bathing. 
  • Cold Surfaces: Since condensation happens as a result of temperature differences, it’s more likely to occur on cold surfaces. This is quite common in homes with inadequate heating. 

How Do You Treat Dampness?

In the case of rising damp, the first thing you want to do is determine whether or not your property was built with a DPC and DPM in place. 

You can probably spot the DPC by searching for a thin strip near the bottom of your building’s external wall. As for the DPM, you’ll need an expert to confirm whether or not you have one. 

Note: The regulations that made it compulsory in the UK to install a DPC and DPM in new houses came into effect when Public Health Act 1875 was rolled out. 

If your home’s DPC and DPM are damaged or worn out, you’ll need to get them repaired or replaced. What’s more, you may need to tank your walls and floors with damp proof materials like damp proof concrete or plaster. 

In the case of penetrating damp, you should start by pinpointing and addressing plumbing and drainage problems. Also, make sure there are no construction issues like the ones mentioned in the previous section. 

Next, you should repair masonry defects such as cracks in the wall using a suitable render. Lastly, install a DPC on your property’s external walls to prevent penetrating damp. 

Damp Proofing Installation Guide in the UK: Types, Prep, Cost, and More

How Long Does Damp Proofing Last?

On average, damp proofing lasts 20-25 years. That being said, there are several factors that can affect its longevity, as we’re about to highlight.

Some of the reasons why damp proofing may last longer:

  • The used damp proofing materials are of high quality.
  • The damp proofing system is installed properly.
  • The damp proofing is receiving regular maintenance.
  • The presence of adequate insulation and ventilation. 

Some of the reasons why damp proofing may not last as long:

  • The damp proofing system wasn’t installed by a professional.
  • The quality of the damp proofing materials is subpar. 
  • The presence of harsh environmental factors like high humidity. 
  • The presence of a major defect in the building’s design.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top