Problems with water in your basement can often be corrected by controlling water above ground, according to a North Dakota State University engineer. “Correcting those above-ground problems may prevent structural damage to your home as well as dry up those basement damp spots,” says Ken Hellevang, an agricultural engineer with the North Dakota State University Extension Service. He notes that saturated soil increases the soil pressure on the basement wall which can lead to cracks, shifts, collapses and other structural problems. Start first by looking to the roof, Hellevang advises. An inch of water on 1,000 square feet of roof amounts to about 623 gallons of water. A foot of compacted snow on that same roof could contain up to 4 inches of water, or nearly 2,500 gallons. “Getting all that water away from the house is a big first step to preventing basement problems,” Hellevang says. “That’s why all eavetrough downspouts should have extensions to carry the water several feet from the house.” Just as the roof is sloped to shed water, the ground around your home should be sloped too, he notes. A slope of about 1 inch per foot near the wall is usually adequate, Hellevang says. Also, the ground should be sloped to carry the water away from the downspout discharge. “In some cases it is desirable to place an impermeable material under the soil next to the wall to ensure that the water flows away from the house,” he says. In addition to good drainage above ground, a drainage system below ground is important to keeping your home dry, Hellevang says. A properly installed drainage system at the house foundation and under the basement floor will ensure a dry basement and eliminate saturated soil conditions next to the wall. A study of leakage problems showed that more than 90 percent were due to improperly installed drainage systems. The engineer says a properly installed foundation drainage system includes drainpipes placed alongside the footing. In areas with high water tables, a drainage system can also be installed around the inside of the footing and under the basement floor. Using granular material to allow the movement of water and filtering material to keep soil from plugging drain pipes is essential to keeping the system functioning for the life of the house Hellevang says. Granular backfill should be used next to basement walls, he notes. Using soils that don’t drain well can cause pressure on the walls if the soils become saturated. Poor- draining soils also increase the potential for moisture or water vapor to move through the wall into the basement. In certain areas, that moisture can carry minerals that are detrimental to the concrete. Window wells also need to be correctly constructed with drains linked to the foundation drains. Soil elevation in the window well should be several inches below bottom of window and sloped to the drain. “The cost of installing the drainage system during new construction is minimal and the benefits are priceless,” Hellevang says. “Because so many problems can result from a poorly designed or installed drainage system, it’s important to install the system correctly or find a contractor who knows how to do the job. “In existing houses with wet basements, correcting the problem may be as easy as controlling the water above the ground,” Hellevang says. “If that’s not successful, then an exterior and interior drainage system may need to be installed.”