Damp proofing materials or DPC materials are used to resist dampness in the building. This article explains various damp proofing materials.
We will discuss various damp proofing materials used in construction.
Let’s start.
Table of Contents
1. Bitumen:
Bitumen is a highly flexible material that is often used as a damp proof course in construction. It can be applied easily with a brush to the bedding of concrete or mortar when it is in a hot condition. A typical thickness for a coat of bitumen is about 3 mm, providing an effective barrier against moisture. However, it can become brittle over time, especially in cold conditions, so it may not be suitable for all applications.
2. Mastic Asphalt:
Mastic asphalt is a semi-rigid material that is obtained by heating asphalt with sand and mineral fillers. It is a perfectly impervious material, making it an excellent choice for damp proofing. However, it should be laid very carefully as any errors in the installation process can result in leaks and other problems. Additionally, mastic asphalt may not be as flexible as other materials, which could limit its use in certain applications.
3. Sheet Membranes:
Sheet membranes are flexible, pre-formed sheets that are used to create a watertight barrier on roofs, walls, and other surfaces. They are typically made from materials like PVC, EPDM, and TPO, and they are highly resistant to moisture, UV rays, and other environmental factors. Sheet membranes can be installed in a variety of ways, depending on the application, and they are relatively easy to install. However, they can be more expensive than other solutions and may require professional installation.
4. Bituminous or Asphaltic Felt:
Bituminous or asphaltic felt is a flexible material that is available in rolls. It is commonly used as a damp proof course on roof slabs and parapet walls, with an overlap of 100 mm on sides. The laps are sealed with bitumen to create a watertight barrier. However, it may not withstand heavy movements, which could limit its use in certain applications.
5. Bricks:
Good quality bricks with low water absorption rates (less than 5 percent) are sometimes used to make damp proof courses. These bricks are laid in two to four courses in cement mortar, creating a barrier against moisture. While bricks can be a cost-effective solution for damp proofing, they may not be as effective as other materials in certain situations.
6. Stones:
Stones such as granite, trap, and slates can be laid over walls to create a damp proof course. This method involves laying the stones over the full width of the wall, creating a barrier against moisture. While stones can be an effective damp proofing solution, they may not be suitable for all applications, as they can be heavy and difficult to install.
7. Mortar:
Cement mortar with a proportion of 1:3 and small quantities of lime and waterproofing agents can be used to create a damp proof course for foundations, ground floor slabs, and the tops of parapet walls. This mortar can also be used for plastering external walls. It is a cost-effective and relatively simple solution for damp proofing, but may not be as effective as other materials in certain situations.
8. Concrete:
A course of 75 mm to 100 mm cement concrete with a ratio of 1:1.5:3 or 1:2:4 can be provided to prevent the rise of water into walls. These courses may be provided with hot bitumen paint as an additional precaution, creating a highly effective barrier against moisture. However, this method can be more expensive and time-consuming than other solutions.
9. Injection Damp Proofing:
Injection damp proofing is a method of creating a barrier against moisture by injecting a chemical damp proof course into the walls. The chemicals react with the moisture in the wall and create a barrier, preventing water from entering the building. Injection damp proofing can be used on a variety of surfaces, including brick, stone, and concrete, and it is relatively easy to install. However, it can be more expensive than other solutions and may require professional installation.
10. Metal Sheets:
Aluminium, copper, or lead sheets can be used to seal construction joints, creating a watertight barrier. Over these sheets, a bituminous seal can be provided for additional protection against moisture. While this method can be highly effective, it can also be more expensive than other solutions.
11. Plastic Sheets:
Plastic sheets made from black polythene with a thickness of 1 mm are a highly effective damp proofing solution. They are relatively inexpensive, easy to install, and highly resistant to moisture. However, they may not be suitable for all applications, as they can degrade over time and may not be as effective in extreme weather conditions
12. Liquid Membrane:
A liquid membrane is a type of flexible, elastomeric coating that can be applied to concrete, metal, and other surfaces to provide a watertight barrier. It is often used as a damp proofing solution for flat roofs, balconies, and other areas that are prone to moisture. Liquid membranes can be sprayed or applied with a brush, and they are highly resistant to weathering, UV rays, and other environmental factors. However, they can be more expensive than other solutions and may require professional installation.
13. PVC Membrane:
PVC membranes are synthetic materials that are used to create a watertight barrier on roofs, walls, and other surfaces. They are highly resistant to moisture, UV rays, and other environmental factors, making them a popular choice for damp proofing. PVC membranes can be installed in sheets or as a liquid, and they are relatively easy to install. However, they can be more expensive than other solutions and may not be suitable for all applications.
14. Bentonite Clay:
Bentonite clay is a natural material that is often used as a damp proofing solution in foundation walls and basements. When wet, the clay expands and creates a seal against moisture, preventing water from seeping into the building. Bentonite clay can be applied as a dry powder or as a slurry, and it is relatively inexpensive compared to other solutions. However, it may not be as effective in extreme weather conditions and can be difficult to install.
15. Cavity Drain Membranes:
Cavity drain membranes are used to create a dry, habitable space in basements, cellars, and other areas that are prone to moisture. They work by allowing water to enter through the membrane and directing it to a drainage system, preventing it from entering the building. Cavity drain membranes can be made from a variety of materials, including HDPE, PVC, and studded membranes, and they are highly effective in preventing water ingress. However, they can be more expensive than other solutions and may require professional installation.