Question
I have recently bought a house and the lawn is full of weed. i have thought of ploughing and regrassing. in ur opinion do i have to take the surface soil away since it contains the weed roots? or is there anyway to finish off the weed roots after plowing the soil?

Answer
Hi Arif, If there is very little desirable grass, then I would spray and kill off everything with glyphosate. Wait a week for the herbicide to do it's thing, then till the area and you would be safe to either seed or sod.  No need to remove any soil. Jim