Horizontal Cracking in foundation walls
Hydrostatic pressure refers to the pressures caused by water pushing against slabs and foundations, particularly underground concrete block or poured concrete walls of foundation and crawlspaces. Water is dense and weighs about 60 lbs. per cubic foot of volume and is therefore capable of generating immense hydrostatic pressure on anything that restricts its natural movement or flow.
look at the grading around the house, look for cracking of the observable exposed foundation, indications of structural movements, how gutters and downspouts are performing, how water is controlled and diverted around the structure, for water puddles near the house foundation, low lying areas near the foundation, indications of moisture intrusion into the crawlspace or basement or slab foundation and floor.