Proper grading away from your foundation is extremely important to prevent water intrusion into your basement or home. Soil should be graded and well compacted at a slope of five percent away from your foundation.
Proper grading is also important in the yard to direct run-off away from the foundation. Grading and sloping techniques such as berms and swales are used to divert water run-off to the sides and around the house.
Over time, the drainage patterns get disturbed which may lead to failures. If this happens, drainage patterns can be re-established by grading. If proper sloping can’t be achieved due to existing circumstances, it may be necessary to install a sub-surface drainage system with catch basins, channel drains and/or French drain systems.
Gutters and downspouts can discharge hundreds of gallons of rain water near your foundation if not connected to a sufficient drainage pipe system. The rainwater discharged from typical downspouts will collect against the foundation wall/footing and eventually seep into your basement.
The only solution to avoid water damage in this situation is to install solid PVC drain pipes buried and connected to the downspouts that lead far away from the house to a lower grade open-end daylight exit.
Common Drainage Questions
What is a swale? It is a gentle sloping ditch usually six-to-eight feet wide with a two percent slope grade.
What is a berm? The opposite of a swale, a berm is an elongated bump used to steer and direct water flow.
What is a French Drain System? This is sloping sub-surface drainage system that often includes catch basins or channel drains piped into a trench that is at least 12 inches wide and 12 inches deep (or more) that is filled with clean #57 VDOT gravel containing perforated and solid drain pipe protected by a geotextile fabric.
What is Downspout Drainage? Generally, a four-plus inch solid wall PVC pipe is connected to the existing downspouts and buried with a 1/8-inch minimum per each foot designed to discharge to daylight or with a pop up emitter away from the foundation.
Should I have a sump pump installed? When all of the exterior drainage issues have been resolved you may have to consider installing a sump pump if water continues to pressurize under the floor and seep into your basement. This is due to an unknown source of water such as an underground spring or water flowing back to the basement from utility trenches.