Before you begin the backfill process, you have to be sure that the foundation cures for at least five to seven days. There are even instances when cracks may occur when you backfill too soon.
The ground over which the filling has to be done should be cleaned off all grass, loose stones, rubbish of all kinds etc. If there is water in the area, it should be pumped or bailed out.
Determine the types of material you will use for foundation backfill. A mixture of various materials such as rocks, soil and stone are commonly used. Some soil can retain too much moisture that is not good for your foundation.
Try to use the refilling material from the excavated earth
The approved excavated material, which has been stocked, shall be cleaned of all rubbish, large size stone, vegetation etc.
Begin backfilling at the corners and be sure that the distribution of the soil is even so as to provide ample lateral support for the walls of your home.
Use an excavator to fill in twelve inches of mixed materials on the sides of the area. After which, compress the soil and stone using the rolling compactor. You must repeat the same backfill procedure until the entire area is completely filled.
Filling should be done in layers, each layer being of 15cm to 20cm.
Each layer is watered and compacted with heavy rammers of wooden logs or steel.
Under no circumstances black cotton soil shall be used for filling in plinth and footing pits.