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What is a Damp Proof Course?

4th October 2023

Categories  Damp/Latest News

What is a Damp Proof Course: Everything You Need to Know

What is a Damp Proof Course? If you’ve ever experienced the misery of dampness and moisture creeping into your home, you’ve probably heard about something called a “damp proof course.” But what exactly is it, how much does it cost, how long does it last, and where should it be installed? In this comprehensive guide, we’ll answer all your questions about damp proof courses and help you understand why they are essential for maintaining a dry and healthy home.

Damp Proof Course

What is a Damp Proof Course?

A damp proof course, often referred to as a DPC, is a vital component of any building’s structure designed to prevent the infiltration of moisture and dampness from the ground into the walls. It is typically a horizontal barrier, usually made of materials like plastic, slate, bitumen felt, or engineering bricks, which is installed within the masonry or brickwork of a building. The primary purpose of a DPC is to create an impermeable layer that prevents moisture, such as rising damp, from rising up through the walls and causing damage to the structure and interior of the building.

How Does a DPC Work?

To understand how a DPC works, it’s essential to know how moisture can infiltrate a building. One common way is through capillary action, where water is drawn up through porous building materials like bricks and mortar. When the moisture reaches a certain level, it can cause unsightly and potentially harmful damp patches on the interior walls, leading to various problems like mould growth, rot, and damage to the building’s structural integrity.



A DPC acts as a barrier to stop this capillary action by blocking the upward movement of moisture. It creates an impermeable layer in the masonry or brickwork that prevents water from rising and causing damage. Instead, the moisture is redirected downward and harmlessly away from the building’s structure.

How Much is a Damp Proof Course?

The cost of a damp proof course can vary significantly depending on several factors, including the size of your property, the type of DPC material used, the complexity of the installation, and your geographic location. On average, you can expect to pay anywhere from £500 to £3,000 or more for a professional DPC installation.

Here are some factors that can affect the cost of a DPC:

Property Size: Larger properties will require more materials and labour, resulting in a higher cost.

DPC Material: The type of material used for the DPC can impact the cost. For example, some materials are more expensive but may offer longer-lasting protection.

Installation Complexity: If your property has unique architectural features or requires extensive work to install the DPC, the cost may increase.

Location: Prices for construction services can vary by region, so your geographic location may influence the cost of a damp proof course.

It’s essential to obtain quotes from reputable contractors in your area to get a more accurate estimate for your specific project. Keep in mind that investing in a high-quality damp proof course can save you money in the long run by preventing costly damage and repairs caused by dampness.

How Long Does a Damp Proof Course Last?

The longevity of a damp proof course can vary depending on several factors, including the type of material used, the quality of the installation, and the environmental conditions in your area. In general, a well-installed damp proof course can last for several decades or even a lifetime.

Here’s a rough estimate of the lifespan of common DPC materials:

Plastic DPC: A plastic damp proof course is a popular choice due to its durability and resistance to decay. It can last for 50 years or more.

Slate DPC: Slate is another long-lasting material commonly used for DPCs. A slate DPC can last for over a century if installed correctly.

Bitumen Felt DPC: Bitumen felt is less durable than plastic or slate but can still provide effective damp protection for 20-30 years.

Engineering Brick DPC: Engineering bricks are extremely durable and can last for a very long time, often well over a century.

Chemical DPC: Advances in technology mean that a Chemical DPC can exceed 20 years lifespan.

It’s crucial to have your DPC inspected periodically to ensure it remains in good condition. If you notice any signs of dampness or damage to your walls, it’s essential to address the issue promptly to prevent further problems.

Where Should a Damp Proof Course Be Installed?

The placement of a damp proof course is a critical aspect of its effectiveness. It should be installed strategically to prevent moisture from rising through the walls. Here are some key areas where a DPC should be installed:

At Ground Level: The most common location for a DPC is typically at ground level, just above the foundation. This prevents rising damp from entering the building from the ground.

Below Floor Level: In some cases, a DPC may also be installed below the floor level to protect against moisture rising through the floor. This is particularly important in basements and crawl spaces.

Around Openings: DPC are likely to be integrated around openings such as doors and windows to prevent moisture from infiltrating through these vulnerable points.

Between Wall Sections: In buildings with multiple wall sections, such as cavity walls, a DPC should be installed between the sections to prevent moisture from transferring from one side to the other.

Chimneys and Party Walls: DPCs should also be used where chimneys or party walls intersect with the main building structure to prevent moisture transfer.

Proper installation and placement of a DPC are essential to its effectiveness. It’s typically recommended to hire a professional contractor experienced in damp proofing to ensure that the DPC is installed correctly and in the right locations.


In summary, a damp proof course is a crucial element in protecting your home from the damaging effects of moisture and rising damp. It acts as a barrier that prevents water from infiltrating your walls and causing structural damage, mold growth, and other issues. While the cost of a damp proof course can vary, it is a worthwhile investment in the long-term integrity of your home.

The lifespan of a DPC depends on various factors, but with proper installation and maintenance, it can last for decades. To ensure its effectiveness, it’s essential to have your DPC inspected regularly and address any issues promptly.

When it comes to the installation of a damp proof course, proper placement is key. It should be strategically installed at ground level, around openings, and in other vulnerable areas to provide comprehensive protection against moisture infiltration.

If you suspect that your home may be suffering from dampness issues, it’s advisable to consult with a professional damp proofing specialist who can assess the situation and recommend the appropriate course of action. Investing in a high-quality damp proof course can help you maintain a dry, healthy, and structurally sound home for years to come.



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