Can You Lay Sod Over Existing Lawn?

Grass and Weeds

• Grass and weeds are removed in preparation for new sod. The sod is one-inch thick so you must remove at least one inch of grass, weeds and soil. Even if the grass and weeds appear dead or brown and dry, you still need to remove the soil. Weed seeds can stay dormant in the soil and could start growing up through the sod when care is given to the sod.

Rocks and Debris

• Hard-tooth rakes are used to spread around the soil and loosen rocks from the soil. All rock and debris such as twigs must be removed from the soil before laying sod. When preparing the soil, even the smallest rocks or pieces of debris must be removed. Any obstructions that could block the sod roots from growing down into the soil can cause the sod to turn yellow, brown and die.

Hard Compact Soil

• After removing grass and weeds, soil can be tilled if the soil is hard and compacted. Till the soil at a depth of three to four inches. When sod is laid over the prepared soil, the soil must be loose so the roots will have an easier time of growing down into the ground to establish a good root system. The sod roots may not be able to penetrate the compacted, hard soil.

Topsoil

• If the soil in the yard is poor quality, such as sandy with poor drainage, dig out an additional one inch of soil when removing the grass and weeds so you can add one inch of fresh, clean topsoil and compost. Amend equal parts of compost and topsoil. The topsoil will have the nutrients to keep the sod healthy until the sod is ready for its first fertilization.