Foundation Level

After excavation foundation should be laid over the soil as considered in the design. Any major variation like level of water table, presence of soft, deleterious, black cotton or filled up soil should be brought to the notice of the designers. The existing services like water supply, sewerage, storm water, gas telephone, electric lines etc. should be suitably protected. 

Foundation should be laid over dry soil. If the level is below the water table suitable arrangement should be made for dewatering by bailing out or pumping or well point dewatering. Care should be taken so that adjacent structures are not be disturbed. 

Over large areas the founding strata may be at different levels. The difference in level should be less than half the clear distance between footings. Over large areas the founding strata may be at different levels. The difference in level should be less than half the clear distance between footings. 

After the excavation of soil is complete foundation should be laid at the earliest so that the exposed soil do not get disturbed by accumulation of rain water etc. If necessary the ground water table should be kept lowered till the foundation is cast beyond the water table and the weight of concrete is more than the upward thrust of ground water.