I would skip the Round-up and just put down a thick layer of newspaper. Water the newspaper and cover with some mulch. Let that sit all summer. In the fall, remove the covering, and seed the area. New lawns do best in most areas when planted in the fall anyway.
I have a 10 round area where a pine tree was removed. The 'grass' that is in the area is full of creeping charlie and everything that shouldn't be there; If I spray Round Up on this area, wait a week or more and then lay down newspaper, cover the newspaper with topsoil and then sow grass seed, would this work? I need to find a way to make this a grassy area without tilling as a result of a spinal injury. Thanks. Rosie
Wait three weeks. You only have to wait two weeks for the Roundup that is in the soil to decompose safely. But I would wait an extra week to see that everything is really dead and that you don't have to spray Roundup again.
What I meant was that you don't have to bother with newspaper. You can sow your grass seed directly on the existing soil, or you can add a little topsoil if you wish.
Glysophate (RoundUp) has virtually no effect on seeds, and you can theoretically spray the weeds and put down grass seed on the same day.
3-4 days should be a more than sufficient wait time. The OP's original idea seems sound, with the wait time mostly to let the weeds die completely. Topping with newspaper should prevent the emergence of new weeds. By the time it decays, the grass will have a good start. Be sure to use the RoundUp on a calm day, as it *will* kill growing grass.HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.