Dampness in buildings is a common problem that can lead to many different types of damage, including structural damage, health problems, and unsightly stains and mold growth. One of the most common causes of dampness in buildings is water ingress through rendered walls. If you’re experiencing dampness in your building caused by this issue, it’s important to take action to prevent further damage and protect your building. In this article, we’ll discuss effective damp proofing techniques for rendered walls to prevent water ingress.
What is Water Ingress?
Water ingress refers to the penetration of water into a building’s interior. This can occur through various means, such as leaks in the roof or walls, cracks in the foundation, or simply through gaps around doors and windows. In the case of rendered walls, water ingress can occur when rainwater penetrates the surface of the render and seeps into the wall behind.
How Does Render Contribute to Water Ingress?
Render is a surface treatment applied to walls to give them a smooth finish. However, if the render is not installed correctly or becomes damaged over time, it can allow water to penetrate beneath the surface. Once water has entered the wall, it can cause a range of problems, including dampness, mold growth, and even structural damage.
What are Some Effective Damp Proofing Techniques for Rendered Walls?
There are several techniques that can be used to damp-proof rendered walls and prevent water ingress. These techniques include:
1. Applying a Waterproofing Membrane
A waterproofing membrane is a layer of material that is applied to the surface of the rendered wall to prevent water from penetrating the surface. This membrane can be made from a variety of materials, such as bituminous or polymer-based membranes. To apply the membrane, the wall surface should be cleaned thoroughly and any cracks or holes filled before applying the membrane.
2. Installing Drainage Channels
Drainage channels can be installed at the bottom of rendered walls to help redirect any water that does manage to penetrate the surface away from the wall. These channels work by collecting water and directing it to a Drain or soakaway system. To install drainage channels, a trench needs to be dug at the base of the wall, and the channel inserted before backfilling with gravel or other drainage material.
3. Improving Water Resistance of Render
One of the most effective ways to prevent water ingress through rendered walls is to improve the water resistance of the render itself. This can be achieved by using render coatings that contain waterproofing agents, or by applying a waterproofing sealant to the surface of the render.
4. Pointing with a Waterproof Mortar
Pointing refers to filling in the gaps between the bricks or blocks of a rendered wall. This can be done using a waterproof mortar that contains admixtures to improve water resistance. This can help prevent water from penetrating the wall through gaps in the mortar, which is a common problem in older buildings.
5. Installing Cavity Drainage Systems
A cavity drainage system involves creating a cavity between the rendered wall and an internal membrane to catch any water that penetrates the surface of the render. This water is then collected and pumped out of the building via a sump and pump system. This system is often used in basements and other areas where water ingress is a common problem.
FAQs
Q: How do I know if my rendered walls are suffering from water ingress?
A: Signs of water ingress may include damp patches, mold growth, peeling plaster or wallpaper, and a musty smell in the affected area.
Q: What causes dampness in buildings?
A: Dampness can be caused by a range of issues, including water ingress through walls and roofs, rising damp from the ground, and condensation.
Q: Can water ingress cause structural damage to a building?
A: Yes, if left untreated, water ingress can cause significant structural damage to a building over time.
Conclusion
Water ingress through rendered walls is a common problem that can lead to significant damage if left untreated. However, there are several effective damp proofing techniques that can be used to prevent water ingress and protect your building. By applying a waterproofing membrane, installing drainage channels, improving the water resistance of the render, pointing with a waterproof mortar, or installing a cavity drainage system, you can prevent water ingress and keep your building safe and dry.