Per the label on Sedgehammer, you are not supposed to reseed or sod within 3 to 4 weeks of using Sedgehammer. Therefore you have only a couple of options. One, is to treat the sedgehammer and stun it with a
glyphosate (round up) type product which allows you to reseed within 7 days with no issues. Or, you can treat with Sedgehammer and wait 3 to 4 weeks before re sodding. If you must sod in 7 to 10 days, then you should treat the nutsedge with a glyphosate product and then you can treat with sedgehammer later if any new nutsedge makes it through the sod you are applying.