Shallow Wells Field Manual
2. Build the Top Slab
The Top Slab should be formed and poured as soon as the well site is determined, usually 1 to 2 months before the well digging begins. The Top Slab is one meter in diameter and about 10 cm thick (about 4 inches) . A ring of bricks is used as a mould to form the top slab.
Make sure the ground is level (a spirit level is the best guide on this). Most builders pour sand for easy leveling and making the ground suitable for concrete. One has to be very sure that the center where a socket ring is placed is hard enough. You can place a brick at the center and make the whole area level. This will not make a socket ring sink upon ramming. Some slabs have been seen with the reinforcement bars seen underneath the slab making it very unsafe to people.
- NB: Most of the top slabs have slanted socket rings therefore never remove a spirit level completely after the first measure of the socket ring. At all this, the Spirit level is your KING.
The concrete for the slab is made with a mixture consisting of 1 part Portland cement, 2 parts river sand and 2 parts of small stones.
PLACING CONCRETE
Place in between the socket ring first and then later on where they fold very close to the socket ring but not touching it. Use the trowel to pull concrete to the socket. Make sure the ring is still level.
The socket with attached bars, called a spider, is placed in the center of the form before pouring the slab. Use a level to be sure the socket is level with the ground. The slab is poured to the height of the single layer of bricks.
While the concrete is drying, it should be kept from drying too quickly by covering it with cloths or grass or straw and keeping the covering wet, for the first week.
Before the concrete dries, write Glory to God in both English and in the local language, as well as the Date on the slab.
