My lawn needs to be redone completely....cannot get rid of crab grass and want a thicker plush lawn. I'm in VA. I've heard of people here claiming they killed lawn(Roundup) and thatched the lawn(removed thatch) and seeded/fertilized. This true? Will I have a problem with the old dead lawn coming back thru the nice new lawn? Gimme the details. I have a tiller and could easily do this but that is lots of work. However, if thats what is best I'll go that route. The yard is full sun....no trees....red fescue???