Starting the lawn again, but need to get rid of weeds first

Hello, everybody,

I am restarting the lawn because I have more weeds and moss than grass there. First of all I need to kill all weeds. If I poison the lawn with Round-up or similar chemical, how soon will I be able to put topsoil and turf? I was thinking to get rid of top soil using a rotovator, but then I will have a problem to remove the excess soil, so I simply want to bring in about 4 inches of new soil and put turf on it (that's why I want to be sure poison will not kill it).

Thanks

 

Most weedkillers are inert in the soil Omega. They only act on green foliage.
Read the labels and see what they say.