Talkback: How to lay lawn turf

I have a very uneven lawn. I am thinking of using a glyosphate weedkiller to till the existing lawn and weeds, then rotovate the area, level it and then lay new turf. Would this work? And how long do I need to leave between using the glyosphate and laying the new turf? Any responses would be gratefully received.

I have laid new turf lawn, it is only seven days ago, it is groing very rapidly, is it too soon to mow it.