If the problem persists, experiment with using a large-capacity dehumidifier to eliminate condensation. If every apparent, logical way of eliminating wetness fails to produce a dry basement, don't waste time or money on random potential solutions. Finding the cause of the problem is absolutely essential to its cure. Make sure the contractor takes the proper test borings of the soil. The hardest type of water problem to correct is one created by faulty construction practices at the time the house was built.
Proper drainage is a crucial consideration in selecting the site for a new house.
This includes not only the drainage of surface water but also drainage of any subsurface or ground water that may already be present or that may accumulate over a period of time and be blocked from its normal course of flow by the new construction. If the subsurface or ground water level is close to the underside of the basement floor slab, water rises through the slab by capillary action, producing dampness. If the subsurface or ground water level is higher than the basement floor, water leaks in through the walls and floor or enters by capillary action, causing standing water in the basement and, at times, dampness in the rooms above. In some cases it is impossible to completely eliminate dampness from a basement whose construction did not take into consideration the basic principles of good drainage. Only after soil borings have been done can anyone knowledgeably predict which, if any, course of action has a chance for success.