The message
from "Mike Lyle" contains these words:

shazzbat wrote:
[...]
You will never remove *all* the roots, so forget it, just take the
worst ones out.

Sound. But see my earlier reply.

Turf won't stop weeds coming back up through, but
putting the membrane back down before turfing will help in this
respect.

I really don't think I'd lay a membrane under turf. The little grass
plants want all the access they can get to the soil. Modern turf in
particular has very little soil attached, and I think most of it
would die in the first dry spell even if it had managed to get a bit
of a toehold. Weeds aren't really as big a problem as all that,
anyhow.

I agree with Mike Lyle. ISTR this is the second time on urg in recent
weeks, that someone has (ill-advisedly, imho}recommended laying turf
directly above membrane :-(

I'd be interested to hear where that idea originates from.

Janet