Grading

Walk your property during a heavy rain and observe where water flows, where it pools, and where it exits the property. Mark problem areas with flags. The foundation should have a visible slope dropping away from the house in all directions. If water pools against the foundation or in the middle of the yard, grading correction is needed.

The minimum grade away from a foundation is 6 inches of drop over the first 10 feet (a 5 percent slope). For general lawn areas, a 1 to 2 percent slope (1 to 2 inches of drop per 10 feet) provides adequate drainage without visible unevenness. Use a string line and line level to measure existing slope and determine how much soil needs to move.

If the grading change is more than 2 inches deep, strip the topsoil layer (typically the top 4 to 6 inches of dark, organic rich soil) and stockpile it nearby. Grade the subsoil to the target slope, then replace the topsoil over the shaped subgrade. This preserves the fertile growing layer that your lawn needs.

Add fill soil to low areas or cut soil from high spots to achieve the target grade. Compact the subsoil in 4 inch lifts using a plate compactor or hand tamper. Uncompacted fill settles unevenly over time, creating new low spots and drainage problems. Let each lift settle for 24 hours if possible before adding the next.

Spread the stockpiled topsoil over the compacted subgrade to a depth of 4 to 6 inches. Rake to a smooth, even finish that follows the target slope. The final surface should be firm but not compacted at the top. Water lightly to settle the soil, then rake again to correct any low spots that appear.

Bare soil must be covered within 2 weeks to prevent erosion. Seed at 8 to 10 pounds per 1,000 square feet and cover with straw erosion blanket, or install sod for immediate coverage. Water consistently until grass is established. For slopes steeper than 3:1, use erosion control blankets to hold soil and seed in place until germination.