Okay I am in southeast Michigan and have a client with new construction and a rough graded lot that wants to install a sprinkler system and new sod. I know I have to grade the lot then add topsoil and grade again. What I don't know is the timing for the company doing the sprinkler system. I mean what order it should be done in. The customer has gotten quotes from companies that will do both but if I'm cheaper on the sod he will split it up. The lot is typical post construction (crushed concrete and other rubble). I want to try and avoid any haul away of the junk and just add 4" of topsoil. I've read that the sprinkler folks can install after I grade and add topsoil then grade again. They will come back and add heads after I lay sod? Anyone know if this is correct?