I have a residential client that wants their poorly established fescue sod replaced with zoysia sod. They want instant carpet so using plugs is not an option. In this area, zoysia sod is uncommon however I have found a reputable supplier who will deliver it to me (don't even ask the price, I might pass out). Here's the question: After the current turf is killed with Round-up, I've been told that the zoysia can be simply laid on top of the dead lawn. I'm not comfortable with that idea--seems like soil contact would be problematic. Assume this is red Virginia clay soil, because it is. I had proposed rototilling and raking out the surface. What would you recommend? I have to do this soon or wait until spring (client won't wait tho--). Thanks for the help.