Cementitious waterproofing is the easiest method of waterproofing and is widely available and easy top mix and apply. It is generally used in areas exposed to high pressure such as sewage and water treatment plants, and tunnels as well as in humid places with high water contact such as terraces, bathrooms, and basements. It has full or semi-resilience but should not be exposed to sunlight and weather conditions so it doesn’t go through the contract and expansion process.
Liquid Waterproofing Membrane
Liquid membrane is a thin coating is used extensively and usually consists of a primer coat and two applications of a top coat which can be applied by spray, roller or trowel. It offers more flexibility than the cementitious types of waterproofing as it cures into a rubbery coating with elongation properties that can reach as high as 280%.
Bituminous Coating Waterproofing
Bituminous coating, also known as asphalt coating, is an economical waterproofing method that dries to provide a tough, seamless, flexible, protective waterproof coating. Liquid bitumen coating is made with bitumen rubber-based materials and can be used on horizontal and vertical surfaces. It is preferred for the insulation of areas such as foundations, cellars, and basements as well as bathrooms, kitchens, and toilets. It is not suitable for sunlight exposure as it becomes brittle and fragile. It offers good adhesion to concrete, brick and plaster, dries quickly and doesn’t require a primer.
Bituminous Membrane Waterproofing
Membrane waterproofing is a preferred waterproofing material for low-sloped roof insulation. It is easy to use and offers a significant price and performance advantage. Membrane waterproofing systems, whether torch-on or acrylic, are the only certain method of waterproofing concrete slabs. They provide durability, dimensional stability at different temperatures (thermal movement) and most are installed with a guarantee.
Torch-on systems are made up of bitumen felt sheets welded together to create a waterproofing membrane. The fibres are usually a non-woven polyester fleece or glass wool, which both have better resistance to puncturing or tearing. This waterproofing membrane, correctly selected, installed and maintained, is now considered a permanent structural element with a life expectancy equal to that of the building it is protecting.
The polyurethane liquid membrane method of waterproofing is used for flat roof areas exposed to weathering. This relatively new product has quickly become another preferred product among waterproofing contractors in South Africa. Polyurethane is a non-toxic liquid-based system that will attach to any cooling material such as concrete, bricks, wood and glass. It is entirely seamless and can easily be applied by either a brush or a roller and is available in different colours.
Polyurethane is designed not to be affected by external factors but it is expensive and very sensitive to moisture – peeling or de-bonding of membranes may happen after time if not correctly applied. Due to strict quality assurance, training is necessary to know which product to use for which application.
For expert advice on the correct cement products to use to achieve the best possible results contact the Sephaku call centre on 0861 32 42 52 or speak to your technical representative.