2% of J.K. Waterproof (1 Kg. of J.K. Waterproof with, 1 bag 50 Kg. of cement) is mixed thoroughly with cement by hand before the cement is mixed with aggregates. Thorough mixing is essential. For thorough mixing cement and waterproofing compound should be heaped on a mixing board and then thoroughly turned over several times with a shovel and finally passed through a fine sieve.