Neil said..
".........If you lay the slabs on a bed of mortar and ballast there will be
no chance of weeds getting though. You will need to ensure there is no
chance of weeds rooting in duff pointing though........"

I'd go with that, and if you do get any weeds then give them a dose of
roundup.


--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk