Quick back story: we had a house built and the front and side yards had sod included. We opted not to pay for sod in the back and just had it seeded. However, the builder didn't add any top soil to bring it up to the same level as ours or our neighbors sod so our back yard grade is about an inch lower.
It is a muddy mess in some places because the neighbor's sprinkler runs off into our yard and the the seed has been washed out so it is growing only in random patches in the yard. Other parts are barren because the soil is sandy and hard. The grass that has sprouted is still pretty tender and small.
My question is, can I lay sod down over top of the existing seed/straw and in some cases new grass to bring the the yard up to level with the side yard and neighbors yard or should I try to remove the existing straw/seed/grass first before laying the new sod? I'd assume at a minimum I'd need to rake up the straw first.