'''Step 6:''' Should the tank still leak, its internal side has to be painted with a water proofer, such as swimming pool paint, non-toxic bitumen, oil paint or 1 part of cement with 10 parts of lime mixed with water.
====Leakage through cracked walls====
[[Image:weld mesh wrapped.jpg|thumb|right|150px|Weld mesh wrapped around a tank. Photo: © E. Nissen-Petersen, Kenya.]]
[[Image:chicken mesh wrapped.jpg|thumb|right|150px|Chicken mesh and barbed wire wrapped around a cracked tank. Photo: © E. Nissen-Petersen, Kenya.]]
'''Problem:''' Water leaks through cracks and fissures in the wall of a water tank.<br>
'''Reason:''' Vertical cracks are due to insufficient horizontal reinforcement and/or incorrect joining of bricks and blocks. Horizontal cracks are due to incorrect joining between the horizontal courses between bricks and blocks.<br>
'''Remedy:''' Build a new tank on the outside of the cracked tank by wrapping reinforcement mesh or wire around the tank and plaster it.
'''Procedure:'''<br>
'''Step 1:''' Drain all water out of the tank and clean it.
'''Step 2:''' Chisel off any loose part on the external side of the tank wall.
'''Step 3:''' Tie sheets of weld mesh together with binding wire and wrap them tightly around the tank and plaster the outside of the tank with 3 cm of plaster 1:3.
*Alternatively, wrap chicken mesh tightly around the cracked tank after which a spiral of barbed wire, gauge 12.5 is wrapped tightly around the chicken mesh with a spacing of 5 cm at the lower half of the tank and 10 cm apart on the upper part of the tank. Thereafter plaster the outside of the tank with 3 cm of plaster 1:3.and keep it moist under shade for 3 weeks.
*Paint the tank with a weather proof paint made of 1 part cement to 10 parts of lime mixed with water.