i removed an old paver patio (10' by 20') and plan on planting new grass after i add topsoil. there is an existing area of grass (20' by 30') next to the old patio, however most if it is below grade. once new topsoil is levelled off over the entire area do i have to lightly pack the soil to prevent future settling? are there any other suggestions to help me in the project? thank you!