The test results should also include the pH level of your lawn. The ideal pH for growing sod is between 6.0 and 7.5. If your soil is too acidic (pH less than 6.0), then you will want to apply lime ...

Add topsoil — You need the soil to be at least 6 inches deep for the sod to grow effectively, so check this first. You can then add topsoil as required to increase the depth and encourage growth.