Posted: 26/02/2015 at 22:45
There would be no real benefit rotavating they soil under the existing lawn
The top soil when laying a new lawn would be firmed down by walking over it to consolidate the area
After this, using a rack , rack over this area and remove any large stones. Then walk over the area again . Keep repeating this process untill the area is firm and level and free of large stones . By continually racking the area you will create a fine tilth ( loose, fine soil to lay you new lawn on top of.
The idea is to have a firm area with no large stones to lay your lawn on to
lay your turf in a stretcher course ( as s bricklaying lays bricks)