I am trying to figure out if I can plant new sod on top of an existing lawn. Can I till the old lawn and lay down top soil then plant the new sod without removing the old grass. I planned on killong the old grass with weed killer.
You can lay the sod on top of your existing lawn. I did exactly this for a lawn that was over taken with weeds. I did not till or lay any top soil down. I did this at the very end of the winter before the weeds could sprout and they had been dormant. the grass on top prevented them from growing. The lawn grew quite well, I did not have any problems with that yard for the 10 plus years after wards.