Controlling moisture movement in foundations is essential for several reasons. First of all, people don’t like water in their basements. However, excessive moisture can also lead to high humidity levels, mold growth, or even rot. One of the methods of controlling this moisture is to damp proof or waterproof the foundation walls. Unfortunately, the terms damp proofing and waterproofing are often used interchangeably in foundation construction, but they mean different things, and they are handled differently. Waterproofing is necessary to keep liquid water away from the foundation. Damp proofing is necessary to protect the foundation from the moisture that is present in the damp soil, even if liquid water isn’t present. The best way of keeping liquid water away from a foundation is to divert downspouts away from the house and slope the ground away from the house. In that way any rain, snowmelt, etc. will not drain down into the soil near the foundation. For any water that does drain down