How can I effectively lay sod over old grass to create a new lawn?

To effectively lay sod over old grass to create a new lawn, you should first prepare the area by removing any debris and weeds. Next, loosen the soil and add a layer of topsoil if needed. Lay the sod in a staggered pattern, ensuring the edges are tightly butted together. Water the sod thoroughly after installation and continue to water regularly to help it establish roots.