Dear visitors! In this blog post we will see meaning of DPC in building construction along with  types of DPC based on material, properties of DPC and methods of DPC installation.

What is DPC in Building Construction? Types of DPC

DPC in building construction stands for "Damp Proof Course". It is a layer of waterproofing material in wall which is commonly laid at the basement level to prevent moisture rising from ground through walls or floors. DPC is installed during the construction process but also it can be retrofitted to the existing buildings to address rising damp issues.

What is DPC in Building Construction?

DPC in building construction is known as damp proof course and it is used to prevent moisture rising through the walls or floors of a structure. Moisture ingress can lead to various problems such as dampness, mold growth, and structural deterioration. DPC typically consists of a 25 mm to 50 mm thick layer or barrier made of materials like bitumen, plastic sheets, slate or cement mortar, strategically placed within the walls or at ground level during construction. This barrier effectively blocks the capillary action of water, preventing it from seeping upwards.

DPC is essential for maintaining the structural integrity and habitability of a building, as it helps to create a moisture-resistant barrier, safeguarding the interior spaces from the damaging effects of water infiltration.

What are the Types of DPC?

Damp-proof course is a barrier to prevent moisture ingress to your building and protect it from dampness, mold growth and structural deterioration. Here are some types of DPC which can used as per requirement.

1. Pressure Grouting DPC

Pressure grouting is a specialized technique used in building construction to address water infiltration and provide a form of damp-proofing or waterproofing. While it is not typically referred to as a Damp Proof Course (DPC), it can be used to mitigate moisture-related issues.

Pressure grouting involves injecting a cementitious or chemical mixture into voids or cracks within a structure or the surrounding soil to create a waterproof barrier or stabilize the foundation. This process is used to address various issues, including sealing leaks in concrete structures, strengthening foundations, and preventing water penetration.

2. Electro-Osmotic DPC

Electro-Osmotic Damp Proof Course (EODPC) is a specialized method for preventing moisture ingress into buildings, particularly in thick walls more than 550 mm or where traditional damp proofing methods like physical or chemical DPCs may not be feasible or effective.

This technique involves the use of electrical principles to counteract the capillary rise of moisture in porous building materials like masonry of rubble stone by utilizing the electric charge of electro-osmosis to send back the moisture.

3. Membrane DPC

A Membrane Damp Proof Course (DPC) is a type of moisture-resistant barrier used in building construction to prevent the upward movement of moisture through walls or floors. Membrane DPCs consist of sheets or membranes made from various materials, including but not limited to bitumen, PVC (polyvinyl chloride), EPDM (ethylene propylene diene monomer), or other synthetic materials. These membranes are installed within the construction elements to create an impermeable layer that blocks the capillary action of water.

4. Chemical DPC

A Chemical Damp Proof Course (DPC) is a method employed in building construction to prevent moisture infiltration into walls and structures. This technique involves the application of chemical compounds, such as siliconates, silanes, or bitumen-based solutions, to building materials like mortar or concrete. These chemicals penetrate the porous material and react with it to create a waterproof barrier.

As the chemicals bond with the substrate, they effectively block the capillary action of water, preventing moisture from rising through the walls. Chemical DPCs are particularly useful in retrofitting existing buildings where physical DPC installation is challenging. Properly applied, they serve as an effective and long-lasting solution to protect structures from the damaging effects of dampness and moisture-related problems.

5. Cavity Wall DPC

A Cavity Wall Damp Proof Course (DPC) is a construction technique used to prevent moisture infiltration in buildings with cavity walls, which consist of two parallel masonry walls separated by an empty space or cavity. In cavity wall construction, a physical or chemical DPC is installed within the cavity to create a barrier that blocks the upward movement of moisture. This DPC can be in the form of a horizontal layer of waterproof materials like bitumen felt, plastic sheets, or chemical compounds injected into the cavity.

By placing the DPC within the cavity, any moisture that penetrates the outer wall is intercepted and redirected downward or drained away before it can reach the inner wall, thus protecting the interior of the building from dampness and related issues. Cavity wall DPCs are a common and effective method for moisture control in buildings, especially in regions with high rainfall or groundwater levels.

6. Integral DPC

An Integral Damp Proof Course (DPC) is a method for preventing moisture ingress in building construction by incorporating moisture-resistant additives directly into the construction materials themselves. This technique is commonly applied during the mixing of concrete or mortar used in foundations, walls, or floors. The additives, such as waterproofing admixtures or chemicals, chemically bind with the building material, creating a moisture-resistant barrier within the structure. Integral DPCs are an inherent part of the construction, ensuring that the entire building material is impervious to moisture, effectively blocking capillary action and preventing dampness from rising. This approach is advantageous as it requires no additional layers or treatments, making it a cost-effective and long-lasting solution for moisture control in construction.

Three Types of DPC Material

There are three types of DPC material based on their physical characteristics. They are called as rigid dpc materials, semi-rigid dpc materials and flexible dpc materials.

1. Rigid DPC Material

Rigid DPC materials are generally made of materials such as slate, concrete or metal and offer a high level of resistance to moisture and pests. These materials are durable and long-lasting and they are commonly used in new construction. These materials may be difficult to install in irregular surfaces or where there is movement and may require specialist skills.

2. Semi Rigid DPC Material

Semi-rigid DPC materials are typically made of materials such as mastic asphalt or cork-board and these materials offer a degree of flexibility, making them ideal for use in uneven surfaces or where movement is anticipated. It is easy to install and it can be cut to size on-site, making them versatile and suitable for a range of applications.

3. Flexible DPC Material

Flexible DPC materials are typically made of materials such as polyethylene, bitumen felt either hessian matrix based, glass or glass-fiber based and offer a high level of flexibility and ease of installation.

These materials are ideal for use in irregular surfaces or where there is movement and can be easily cut to size on-site. The flexible DPC materials are also resistant to damage from moisture and pests, making them a popular choice in many construction projects.

What is the Height of DPC in Buildings?

Most of people having confusion about the height of DPC layer height in building. The DPC layer should be installed at least 150 mm above the ground level in structure. This height of DPC layer prevents moisture from rising through the walls by capillary action. 

But the height of DPC may vary as per the structural requirements, moisture availability in the ground,  source of dampness and future considerations etc.

In the TFC (timber-framed construction), the height of DPC is 225 mm above the ground level.

What are the Properties of DPC Materials?

Different materials having their own properties but some common properties of the DPC materials are given below:

Impermeability

DPC materials should be impermeable to water and water vapor to prevent moisture from rising through walls and floors.

Durability

Materials should be able to withstand exposure to moisture, temperature changes and other environmental factors without deteriorating.

Flexibility

Flexible DPC materials such as plastic should be able to conform to the shape of the building and accommodate any movement or settling without cracking or breaking.

Compatibility

DPC materials should be compatible with other building materials used in construction and not cause any adverse reactions or chemical interactions.

Free From Salts

The damp proof coarse materials should be free from salts like sulfates, chlorides and nitrates.

Easy to Install

The materials should be easy to install and work with, either during construction or as a retrofit to existing buildings.

Resistance to Pests

DPC materials should be resistant to pests such as rodents and insects which can compromise the integrity of the material and cause damage to the building.

What are the Methods of  DPC Installation?

There are following methods of dpc installation:

1. Horizontal Method
2. Vertical Method
3. Chemical Method
4. Integral Method
5. Surface Method
6. Sheet Membrane Method
7. Injection Grouting Method
8. Layered Method
9. Combined Method

Application of DPC in Different Construction Areas

DPC is used in different area of construction at different level. See the list of structures below:

DPC in Foundation Walls

DPC is installed at the base of foundation walls to prevent moisture from seeping into the structure through the walls.

DPC in Basement Walls

Basements are highly susceptible to dampness and moisture, which can lead to mold and mildew growth and even structural damage. Therefore, DPC is essential to prevent moisture from seeping through the basement walls.

DPC in Floors

DPC is also installed between the concrete slab and the foundation walls to prevent moisture from rising through the floor. This is especially important in areas where the water table is high or where the soil is damp.

DPC in External Walls

It is installed at the base of external walls to prevent moisture from entering the building through the walls. This is particularly important in areas with high rainfall or high humidity.

DPC in Chimneys

DPC is installed around chimneys to prevent moisture from entering the roof space through the chimney.

DPC in External Doors and Windows

Around the external doors and windows, DPC is used to prevent moisture from entering the building through the gaps between the frames and the walls.

DPC in Balconies and Terraces

DPC is installed below the concrete slabs of balconies and terraces to prevent moisture from seeping through the floor and causing damage to the underlying structure. Also, DPC is provided is roofing, retaining wall, boundary wall and cavity walls etc.

Note: The suitable materials are used for every type of structures based on budget and requirement.

👉FAQs

What is Full Form of DPC in Civil Engineering or Construction?

DPC Full Form in Civil Engineering is "Damp Proof Course." DPC is a layer of material act as barrier in structure which is used to prevent the entrance of moisture form the ground or any other sources.

What are Three Types of DPC Materials?

The three types of DPC materials are:

1. Rigid dpc materials,
2. Semi-rigid dpc materials and
3. Flexible dpc materials.

All having their own specialty and application in the construction industries.

What is DPC Waterproofing?

DPC is a layer of waterproofing material in a structure to prevent rising dampness. The source of dampness in structure may be ground water or sewage water generally.

Why is DPC Used For Wall?

The most common materials used for DPC in external walls are bitumen felt and PVC. Bitumen felt is still widely used due to its low cost and ease of installation while PVC is becoming more popular due to its superior durability and resistance to moisture. Some people also use cement concrete as DPC in wall.

Which Dr Fixit is Used in DPC?

As per company instruction, "Fixit Bitufix Bitumen Emulsion Paint" is used as DPC Waterproofing.

What is DPC Thickness?

40 mm thickness of DPC is provided uniform above ground level with wall thickness. Generally DPC is provided of 25 mm to 50 mm thickness depending upon materials used.

What is Thickness of DPC at Plinth Level?

It should be uniform 50 mm to 75 mm at plinth level.