You may want to consider sharing the rental cost with a neighbor who is interested in aerating the lawn. Soil layering means that soil of finer texture, which comes with imported sod, is layered over the existing coarser soil. This layering disrupts drainage, as water is held in the finer-textured soil. This leads to compacted conditions and poor root development. Aerating breaks up the layering, allowing water to flow through the soil more easily and reach the roots. Often, the topsoil of newly constructed lawns is stripped or buried, and the grass established on subsoil has been compacted by construction traffic.