Couple of things.
1) Mains is DANGEROUS!
Ok, now that's out of the way.
2) Do you really need 13A? A lot of plugs are not actually fitted with a 13A fuse, they are just commonly referred to as a "13A plug", for example, look on your laptop power supply, it might supply something like 19V @ 4.3A on the DC side, but AC will be 230-250V @ 0.6A or something, so you could get away with 2A which is <1mm.
3) If you are using a AC to DC converter on a PCB, don't forget isolation slots!
4) Not necessity, but I always put a PCB fuse or panel mount fuse to the equipment as if that does short out things can get a bit toasty!
If you do require 13A, then go with 10mm traces as a MINIMUM I would say for 1oz copper, I would plate the traces as people have said here, or use 2oz copper.