A leaking surface, if left unattended for long, not only damages the entire structure but also leaves a permanent mark behind reminding you always about the poor quality of construction. Therefore, waterproofing is an important aspect of construction as well as building maintenance. In India, where the whole country gets soaked in Monsoon rains for nearly four months in a year, the concept of waterproofing has special significance. As the building technology is evolving with which materials used in building too are undergoing change, there is need to move away from the conventional waterproofing techniques and adopt modern waterproofing technologies to suit the changing needs. Fortunately, there have been many modern techniques of waterproofing available which can be adopted profitably in our country too.
Some of the modern waterproofing methods are:
Cementitious waterproofing products are popular because they are the easiest materials to use. They comprise a mix of dry cement and sand, and liquid latex. Often acrylic additive is added to the product to enhance its bonding also to get a more solid, durable coating. Cementitious products are used for protection against chemical attack and also as a structural waterproofing. This method is often used in the internal wet areas such as toilets. They are usually available in hand or spray-applied waterproofing coatings. In India, Dow Chemicals, Perma, Supreme and Dubond are some of the known brands for cementitious waterproofing.
Liquid Waterproofing Membrane
Liquid waterproofing membrane are protective coatings and are either of one or two components, usually Acrylic, Polyurethane, Bituminous base, or a combination of them. They can be used in all areas of roofing, planters, sunken areas, landscapes, pedestrian areas, car parks and structural waterproofing. They are usually used due to their ease of application. It also ensures greater security against infiltration or damages to liquid membrane. They are seamlessly applied without any joints, thus reducing the risk of leakages from joints. It can be applied by the semi skilled labour. It also saves lot of time in its application and there is no need of curing.
It is a a mixture obtained by modifying high quality bitumen with plastomeric and elastomeric polymer additives. A layer of bituminous water proof membrane is laid over the surface (after clearing it of the dirt and dust) which acts as a shield against the seepage of water. Since membrane is flexible it can cover any small crack on the surface. It should not be applied when the climate is very hot. Further, a proper slope is necessary to allow the water to flow steadily to drains.
Bituminous coating is also known as asphalt coating and is an excellent protective coating and waterproofing agent, especially on surfaces such as concrete foundations. It provides protection against vapour and water. Bituminous coating is also often used on carbon steel pipes to provide cathodic protection. Quick drying, flexibility, easy to apply, strong adhesion and non-flammability are some of the qualities of bituminous coating which make it preferred waterproofing material. Further, it remains watertight under permanently wet conditions which is an added advantage.
Polyurethane Liquid Membrane
Polyurethane is a popular waterproofing material due to its ease of installation. Unlike other waterproofing systems like sheet membranes and liquid applied membranes, this polyurethane application requires comparatively less skill and supervision. It’s also preferred due to its durability and wear resistance qualities. It can also be used in potable water tanks, water channels, sewage tanks, roofs, balconies, terrace, etc. However, it is slightly expensive when compared to other options.