Soil for a New Lawn

Preparing Soil for a New Lawn

Establishing a new lawn requires a quality topsoil base that gives grass roots the best possible growing conditions. A typical backyard lawn area of 10 metres by 8 metres encompasses 80 square metres. At 100mm depth, which provides adequate topsoil for most turf varieties to establish strong root systems, you'll need approximately 8 cubic metres of topsoil to prepare this lawn area properly.

Eight cubic metres of topsoil weighs approximately 8.8 tonnes, a substantial delivery that will require a large tipper truck and clear access to your property. This volume will form a significant pile that needs prompt spreading before laying turf or seeding. Most suppliers can arrange delivery timing to suit your turf delivery or seeding schedule.

Why 100mm Depth Works for Lawns

Unlike garden beds that need deeper soil for varied root systems, established lawns do most of their growing in the top 100mm of soil. This depth provides adequate growing medium while remaining economical for large areas. If your existing soil is particularly poor, such as heavy clay or building rubble, consider going slightly deeper to give your lawn the best chance of establishing well during its first summer.

Spreading and Levelling Tips

Proper levelling is critical for lawns and more challenging than garden beds because the finished surface will be visible. Spread the topsoil in rough layers first, then use a landscaping rake to level the surface. A long straight edge or string line helps identify high and low spots. Allow for slight settlement by finishing the level about 20mm higher than your target, and avoid walking on prepared areas once levelled. Roll the area lightly before laying turf to firm the surface without over-compacting.

Planning a differently sized lawn? Use our main soil calculator to enter your exact dimensions.