What is Waterproofing and how does Waterproofing work?
Waterproof over existing waterproofing in short does work, as long as we solve the main water leakage issues. As we talk about waterproofing, let us break down what is waterproofing. Waterproofing is an important process in both construction and renovation. It shields structures from water damage, which can lead to mold growth, structural damages, and expensive repairs.
Waterproofing is used in a variety of areas, including roofs, basements, bathrooms, and terraces. However, over time, even the best waterproofing systems will not be effective. It is possible to waterproof over a waterproofed area, but its effectiveness depends on several factors, including the condition of the current waterproofing system, the products being applied, and proper surface preparation. The following will discuss the methods of application and its effectiveness.
In some cases, the existing waterproofing product may not be suitable with the new product being applied. It is important to make sure that the new product is works with the existing system.
Lastly, it is crucial to consider the purpose and exposure of the area being waterproofed. Areas that are exposed to the sun, such as rooftops, will require different products than wet areas like bathrooms and water tanks.
Why Waterproofed areas still fail?
Waterproofed areas can still be affected for many reasons, even when high-quality materials and correct techniques are used.
One common reason is poor surface preparation. If the area is not thoroughly cleaned, dried, or primed before the waterproofing is applied, the product may not gel correctly, leading to peeling or leaks. Another issue is incorrect application. Applying the waterproofing layer too thinly, unevenly, deter its effectiveness, particularly in weaker areas such as corners or junctions.
Movement or cracking in the structure can also cause failure. Buildings naturally shift, expand, and contract over time. If the waterproofing membrane is not flexible enough to accommodate these movements, it may crack and allow water to enter.
Penetrations in the surface such as around drains, pipes, or joints are also weak points. If these are not waterproofed properly, or if the sealants age over time, water can enter through those gaps. Additionally, using incompatible materials can lead to failure. Some waterproofing systems do not bond well with certain surfaces, especially those contaminated with oil or residues from previous installations.
Environmental exposure is another issue. Waterproofing products that are not UV-resistant can degrade when exposed to sunlight, becoming fragile or cracked over time. Lack of maintenance can also contribute to failure. Waterproofed areas may become damaged, worn out, or clogged, especially if debris accumulates or repairs are neglected.
Finally, poor design or drainage can undermine even the best waterproofing systems. If water is allowed to pool due to insufficient slope or blocked drains, it increases the chances of it finding and exploiting weaknesses in the system.
Different types of waterproofing methods
There are several methods of waterproofing and materials used for different scenarios, some of it such as the liquid applied membrane, cementitious water proofing systems or Bituminous membranes are used for varied surfaces and depending on exposed (outdoors) or concealed (indoors), we will consider using the specified method.
Liquid-applied membranes
Liquid-applied membranes, such as polyurethane and acrylic, are common materials used for waterproofing. If the existing waterproofing is made from either of these materials, you can typically apply a new layer over it. For best results, begin by cleaning the surface thoroughly. This can be done using a power washer. Any loose material should be removed, and the surface should be lightly sanded to help the new layer adhere. It is also important to apply a primer if recommended by the product manufacturer. Applying the new waterproofing in thin coats, allowing each coat to cure fully before applying the next, will help achieve the best results.
Cementitious waterproofing
Cementitious waterproofing systems are often used in areas like bathrooms, water tanks, or retaining walls. If the exisitng waterproofing is a cement-based system, you can apply a new layer of cementitious waterproofing over it. The surface should be cleaned to remove any dust, or loose particles, which can be done using a wire brush or mechanical means. It is also a good idea to dampen the surface slightly before applying the new layer to ensure proper adhesion. If bonding to an older cementitious layer, a bonding agent should be used to improve the gelling of the new layer. The new waterproofing should be applied in two or more coats using a brush. While cementitious systems are ideal for wet environments and are breathable yet waterproof, they are rigid and not suitable for areas that experience significant structural movement. If you plan to tile over the waterproofing, a cementitious system is a better choice, as it can easily be tiled over.
Bituminous membranes
Bituminous membranes, which include both torch-on and self-adhesive products, are commonly used for waterproofing roofs and foundations. If your existing waterproofing consists of a bitumen-based membrane, you can apply a new layer of bituminous waterproofing over it. However, this process requires some attention. First, inspect the existing membrane for any cracks, bubbles, or areas that may be delaminating. These areas need to be repaired or replaced before proceeding. Once the surface is inspected, clean it thoroughly and apply a bituminous primer to improve adhesion. When using a torch-on membrane, ensure that the seams are properly overlapped and heated to ensure a secure bond. If you are using a self-adhesive membrane, be sure to roll it out carefully while pressing down to remove air bubbles. Bituminous membranes are durable and highly resistant to water, making them ideal for long-lasting protection in areas such as rooftops and foundations. However, torching the membrane requires specialized skills and equipment, which may be a drawback for some DIYers.
How does SWC does it differently?
Regardless of the type of product chosen, there are some general preparation steps that must be followed to ensure the success of the waterproofing application. First, we will inspect the surface for any cracks, bubbles, or weak points in the existing waterproofing layer. Any areas that show signs of failure will be repaired before proceeding. Next, the surface must be cleaned thoroughly to remove any dust, oils, or debris. A power washer or stiff-bristle brush with soap can be used for cleaning. After cleaning, any damaged areas should be patched with compatible materials. If necessary, a primer should be applied to improve adhesion between the old and new waterproofing layers. Once the surface is prepared, the new waterproofing can be applied. It’s essential to follow the product’s instructions carefully, paying attention to curing times and recommended application methods. In some cases, applying multiple coats may be required.
Waterproof over existing waterproofing can be an effective and cost-efficient solution if done properly. The key factors to success include choosing the right products, ensuring compatibility with the existing system, and preparing the surface adequately. Whether you are working with acrylic, cementitious, bitumen, rubber, or hybrid systems, taking the time to follow proper procedures will ensure that your waterproofing performs effectively for many years to come.