Hi just bought an house and at some point the bath has been removed and replaced with a shower ,there is still enough room for a bath so I'm putting one back in ,do both hot and cold bath tap pipes need to be done in 22mm as at the moment the cold feeding the shower is 15mm and the hot feeding the shower is 22mm with a reducer down to 15 mm ,my plan is to take a feed off them as they was originally the bath supply , but not sure if just the hot should be 22mm or the cold too....thanks for any information