The type of cracks you describe and their location typically result from minor shifting of the home. This may surprise you, but your home is constantly moving on the soil upon which it sits. To what extent, and how often, is determined by a number of factors: type of soil, topography of the ground that surrounds your home, drainage or watershed systems, and, to some extent, the change of seasons.
Profuse amounts of water under and directly around the foundation of the house can cause the house to shift and result in cracking just as you have described. Your cracks probably have recently appeared because the warm weather has dried the soil and the composition of the soil caused movement of the home.
You can help to avoid this problem by taking the following steps:
- Install rain gutters and downspouts around the house.
- Grade all soil at the perimeter of the house away from the house to avoid water running into the crawl space. This goes for concrete patios and walkways too - they should be poured so that water runs away from the house.
- Don't flood the landscaping surrounding the house.
- If lots surrounding yours are higher, or drain onto your property, an extensive drainage system may be in order.
- Make sure that there is proper ventilation under the house so that moisture or dampness does not collect.
The most common method of crawl space ventilation is vents at the perimeter of the foundation.
