Brett, copper shielding would be better, you can get slug barrier tape from the big green shed is cheap

http://www.bunnings.com.au/on-guard-...-trap_p3010314

I've not tried it but others have had success with it

EDIT Weirdy you beat me to it by 1 minute

PS heard Masters may be closing down they are losing hundreds of millions, I bet DB is really sympathetic hahha