Ensuring there is proper drainage around your foundation is critical to maintaining a dry basement or crawlspace and to prevent movement or damage to the footings of your home. Water standing against the foundation will eventually find its way in to your home through cracks or imperfections in the concrete. If you have a finished basement, damage to wood framing and finishes can go unseen for long periods of time. Wood rot, mold growth and a perfect environment for insects can result. If you live in a cold-weather climate, this water can freeze causing movement of the footings that can result in structural damage.
You should take a walk around your home in the rain periodically to check for depressed areas that may be allowing water to stand against the foundation.
When homes are built, the ground is excavated larger than the footprint of the finished structure to allow the space needed to construct the foundation. When the foundation is complete, the hole is back-filled with some of the dirt that was removed for the excavation. If this soil is not properly compacted or contains organic debris, it will eventually settle and cause the ground to slope toward your foundation. Any depressed areas should be filled to direct water away from the foundation. Care should be taken to keep adequate space between the soil and the bottom row of siding. If this clearance cannot be maintained, an area 10 to 15 feet away from the home should be re-graded to ensure positive drainage.
If you have gutters, the downspouts should drain 6 to 10 feet from the home to well-drained areas that will carry the water away from the foundation. If your home does not have gutters, proper ground slope is critical to shedding water away from the home. Sump pump discharge lines should also be directed as far away as possible to prevent the expelled water from collecting at the foundation wall. Driveways or sidewalks that have sunk and are now pitched toward the home should be raised or replaced to direct water away from the home.