The leakages in water tanks can be outward from the structure, when the structure is full and inwards, when they are partially full.

Water can also seep in from the ground in case of underwater tanks.
This causes contamination of water in the tanks, and allows passage of dirt and other impurities to pass through. This may lead to health related problems, for residents of buildings.

Water is an everyday necessity, and a prime element for a living human being. Thorough inspections and professional expertise needs to be taken for handling these structures.

1. Empty the entire tank and allow it to dry for some time.

2. Clean the sides and base with wire brush to remove loose particles from the parent structure of the tank.

3. Check the soundness of sides and base with the help of hammer.

4. Seal cracks, if any with suitable putty.

5. Apply Epoxy based coatings on the inside surface. For example an coating such as Waterseal ( This is tested by Haffkin Institute for Non toxicity ) can be applied on the entire surface. There should be proper ventilation, during the work, for which manholes on the top of the tanks, should be kept opened.

6. The gap between the 2 coats should be 24 hours.

7. After 24 hours of last coat, wash the tank with detergent and twice or more with water, before putting to use.

Repairs to Corrosion damages for WATERTANKS

Leakage of water and overflow of water from tank are major reasons for corrosion damage to water tanks.

• Leakage can be arrested as per the method given in watertanks waterproofing section above.

• Usually, due to water vapour and chlorine present in the water, the underside of the tank top cover (not below the tank) shows severe corrosion damage. Treatment method is similar to the procedure for repairs to concrete damaged by corrosion. Additional protective coating based on acrylic base is required from underside.

• Damage to RCC walls and base slab are also attended in a similar manner.

• Provide automatic level controller to prevent overflow of tank.

Some typical guidelines and precautions to be taken related to watertanks:

• Overflow from the overhead tank should not fall freely on the terrace damaging its floor. The overflow pipe should be led to the water outlet (downtake pipe ).

• There should be suitable space between the terrace floor and the overhead tank to facilitate repairs.

• In the case of underground water tank, the ground should slope away from the tank for approximatey around 3 mts, so that the water is diverted away from the tank.