Therefore it must be realized that as little water as possible should be used for mixing, but the use of water should be generous for curing. It is not commonly known that cement plaster, ferro-cement and concrete have to be kept wet for at least 28 days, never being allowed to dry since the process of hardening will stop as soon as the mortar/ concrete dries, If, as in our case, waterproof plaster has to be achieved, the material must be kept wet for one year. But even after a year cement plaster should not be allowed to dry off. Remember curing is as important as material testing and mixing the right composition of mortar or concrete. The chart gives an indication of how important curing is.

The cured cement plaster achieved the following hardening results:

After 3 days	20% of final hardness
After 7 days	45% of final hardness
After 28 days	60% of final hardness
After 3 months	85% of final hardness
After 6 months	95% of final hardness
After 1 year	100% of final hardness