"brian stanton" wrote in message
...

First time on the forum and no idea about gardening.....my front lawn is
in a really bad state. The lawn is low down in the garden and i wish to
raise the level of it up. If I put 200mm of top soil on top of the
existing lawn with an intention to re-turf afterwards would the lawn
underneath grow through or would I have to remove the old existing turf
beforehand?

You could spray it with something like Roundup a week or so before putting
in the new soil to kill the old stuff.