Just wondering if anyone has done this before and if there are any
potetial problems with doing it. Also i am installing a combi boiler
and was wondering what sort of pipe size i should use for the
shower/bath.

I would think 10mm would be to small for the shower/bath but doing
really want to go over 15mm due to space. what would be a reason for
having say 22mm pipe over 15mm.

Thanks for your help.

Pete