Step 4: Cure the Concrete
Don’t stop reading yet or you will miss one very important point. You need to “cure” the concrete. If the concrete isn’t kept moist for a few days it may crack. The problem is that the surface will dry out while the bottom is still wet causing tension which basically tears the concrete apart. There are several ways to cure concrete. The easiest is to simply spray it very lightly with a hose. You can cover it with a wet cloth such as burlap (don’t let the burlap dry out). Or you can use chemical curing agents such as Sakrete Cure `N Seal. The question of how long to do this and how often is a tough one because it depends on temperature, humidity and air flow. The hotter and dryer and windier it is the more you will have to re apply water.
Sakrete of North America