A watery crawlspace
Today's problem: some water in a crawlspace.
A reverse slope on a concrete patio was the culprit. This 12x20 concrete patio was sloped towards the foundation, carrying all the water from the patio to the foundation, flooding through a typical shrinkage crack in the foundation. The easy solution for this problem was to have the concrete patio slab-jacked (pump concrete under the concrete patio slab, raising the surface to create a positive slope, draining water away from the foundation). As a rule of thumb, your house should be an "island" with all grades sloped away from the foundation, at a rate of 1/2" per foot for five feet.