Waterproofing cement block walls will help extend the life of the walls and help to prevent expensive water damage that can occur if cement block walls are not properly sealed. Instead of hiring an expensive waterproofing company, choose the cheaper route and waterproof the cement block walls yourself with the help of commercial waterproofing products.
Several commercial waterproofing products are available under different brand names and in a variety of types, including waterproof paints and sealers. Thoroseal offers a waterproof, cement-based coating that will waterproof various concrete and masonry items including walls, basements, brick and stones. Another option is RedGard Waterproofing and Crack Prevention Membrane, which not only waterproofs the surface but also has an anti-fracture membrane to help prevent cracks. Olympic offers a multisurface waterproofer that you can use on concrete, brick and wood. This waterproofer not only protects and seals the surface against water damage, it also provides a mildew-resistant coating. Another brand of waterproofer is UGL. Among UGL's various types of masonry waterproofing products is a low-odor waterproof paint designed for use on brick, concrete and other masonry surfaces.
Before you can correctly waterproof cement walls, you must first repair cracks and holes in the surface as well as thoroughly clean the block walls. To check the structure of the cement walls, place pieces of masking tape on several locations of the cement. If no cement comes off when you pull the tape off, the surface of the concrete is suitable for waterproofing. However, if concrete does come off, you must repair the walls before you can properly waterproof them.
Once you have repaired and cleaned the cement block walls, you are ready to waterproof them. The method you use to apply the waterproof paint or sealer will depend on the type of waterproofing product you are using. For example, use a nap roller to apply waterproof paint to a block wall, or use a stiff brush to apply waterproof sealer. No matter what method you use, apply the liquid to the surface from the top to the bottom until the entire wall is covered. After the block wall has dried for an hour and is not wet when you touch it with your finger, apply a second coat in the same manner. In some instances, a third coat may be required.
For best results, follow the instructions and warnings included in the product's manufacturer instructions. When applying the waterproofing, make sure to fill all voids and pores of the cement block.
Refrain from waterproofing fresh cement. Fresh cement must cure before it can be waterproofed, sealed or painted.
Choose the waterproofing product that best fits your budget and needs. For example, if you want to waterproof the cement without altering the color or look of the wall, use a waterproof sealer made for concrete and cement use. However, if you want to color the walls, use waterproof paint.
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