Exterior: Grading & Water Management
Why Is Grading So Important?
Keeping your house dry is arguably the top maintenance priority for any homeowner. Poor water control can slowly cause serious damage to foundations, basements, slabs, crawlspaces and siding. Two methods are especially effective at managing water: grading around the house and yard, and gutters with downspouts.
Landscape Grading
The ideal is for the landscape to drop about 6 inches over the first 10 feet from the house. Depending on conditions, other approaches such as swales or physical barriers may be needed.
Swales
Swales use the slope of the grading to channel water to a safe runoff area. They are commonly used to direct runoff coming down a hillside or flowing between two closely spaced houses.
Downspouts
The most common grading flaw, and the easiest to fix, is missing downspout extensions. Extensions simply carry rainwater from the gutters away from the house and foundation. Extensions of about 6 feet usually work, though some situations call for longer ones.
Subsurface Grading
Grading can look correct on the surface while water still finds a path back to the house underground. For example, mulch may appear to slope away from the house while the soil beneath it slopes toward the foundation. This is difficult to detect during a home inspection, so homeowners should keep an eye on water flow, grading, basement moisture and similar signs. In some cases, plastic sheeting under the landscaping around the perimeter of the home can block the underground paths water tends to follow. For a tricky grading problem, consult a qualified contractor who can put together a plan.