Preparing for lawn.

Hi to all. I am new to site and have a question which i hope some of you may offer some advice.
I am in the process of preparing my plot for turfing. I have dug down and removed a concrete path that was 12 inches below the surface of the old lawn that i have dug up and skipped. Having removed bricks, cobbles, pebbles, large stones and loads of roots. The soil was very compacted so i have dug it over and broke it up in the process. Obviously I cannot remove every single root and weed but is there anyway that I could stop weeds that may be in the soil regrowing?
I have been told that if I cover the patch with visqueen to block out the light this will kill all the roots and weeds in the soil. If so how long will I have to leave it on for? I am planning on doing the turfing in September or October so I have time to let it settle and the add some topsoil if needed.
Thanks.

 

Never tried the visqueen approach. Black polythene is a recognised way of killing weeds. I would think two or three weeks would be enough to kill small weeds, but I would guess it could take longer to kill off dandelions, docks and other deep-rooted weeds (they seem to survive at least that long in the dark of the compost heap). In that time the ground would presumably dry out pretty much, so it would have to be soaked before the turf went down. Rather than use plastic (how much will you need? What will it cost?) I think I would just leave the plot for a few weeks, and any residual weeds will appear and could be hoed up or given a dose of glyphosate a couple of weeks before the turf is due.

 

Personally Id just leave it open to the elements and spray or dig up the weeds that come up, just as Beechleaf sudgests.

Not a fan of the old carpet / plastic aproach as it looks awfull and IMO isnt that efective.