Waterproofing chemicals are used extensively.
The water-proofing compounds can be basically bifurcated into:
· Tar/bitumen based compounds.
· Inorganic compounds with little percentage of chlorides and sulphates.
· Acrylic based compounds.
· Expoxy resins.
· Polysulphides.
· Polyurethanes.
· Silicones.
Cost-wise Tar based compounds are cheaper; they are not very reliable. The silicon based compounds are almost 100% reliable, but they are very expensive. All the other compound range between these two. Water-proofing chemicals are applied superficially (from top) and are better for local use but one cannot stop the leakages of the complete structure with these chemicals.
Some chemicals are recommended for mixing with cement, at the time of concreting. The traditional method of brickbat coba is still the most popular of waterproofing methods in india. Water-proofing compounds are generally available in powder and liquid form as they serve the dual purpose of water-proofing and heat insulating.
