Site grading is the process of adjusting the slope and elevation of the soil around a home or building. Prior to construction or renovation, site grading may be performed to even out the surface and provide a solid foundation. For existing buildings, grading may be required to improve drainage and create the desired appearance for landscaping features.
Successful grading projects often require input from professional engineers or earthwork contractors. These individuals inspect the land to evaluate soil conditions and moisture problems. Geotechnical or civil engineers may also refer to local contour maps to learn more about elevation changes and how rainwater reaches local water bodies. Based on the advice from these professionals, homeowners to earthwork contractors can regrade the property as needed.
One of the primary concerns of site grading is to control the flow of storm water. Left uncontrolled, storm water may collect around the foundations of a building, leading to rot or safety issues. Excess moisture within the soil can also impact the ability of plants to grow, and can lead to a spongy or marshy soil texture.
Using site grading techniques, contractors may add French drains to capture excess moisture around the home and direct it to local storm water channels. French drains consist of metal or plastic pipes that provide a safe path of travel for storm water, and help to keep this moisture out of the earth. These drains are placed within the soil, and the earth must be regraded to direct water into the drain. Site grading may also include adding channels, ditches or vegetated swales to capture or filter storm water and keep it away from the home.
Contractors rely on a variety of equipment when performing site grading work. Excavators and bulldozers are used to remove or redistribute dirt, or to fill low spots within the sites. Dirt may also be loaded into a dump truck for removal from the site. Grading machines can also be used to level and tamp the earth to create a smooth, even surface, or to cover drainage systems. In some applications, cranes and other large equipment may be required to move heavy boulders during a site grading project.
Depending on the quality of the soil within a site, it may be necessary to remove existing soil and bring in a new layer of topsoil. If the soil is too thick to permit adequate moisture absorption, a layer of gravel or fine topsoil can add absorption and minimize moisture problems. Additional vegetation and changes in slope can also help to remedy these types of issues.