In the Denver area, most claims against home builders are due to foundation problems. Contractors across the country face a similar dilemma.
The cause of most foundation problems is water. Keeping water drained away from foundations is necessary because, of course, any water pooled against the concrete will eventually penetrate the waterproofing, but more importantly, wet soil, especially clay, can expand and contract as it takes on water, and the weight of the water can exert significant hydrostatic pressure on the foundation. With all of these potential problems, it makes sense to install a good drainage system.