We are researching replacing our ensuite, shower, enclosure, tray, basin, WC and replacing a radiator with a towel rad. Currently, the shower waste runs inside a small bulkhead (made of a skirting board) on the floor along 2 walls (approx 6 foot, then a 90 degree turn a further 4 foot). The 6 foot run is against the direction of the floor joists so this would need running through the joists. I have yet to lift the chipboard floor so don't know what size the joists are. What is the maximum permissible hole I can make in a joist to accept the waste pipe. House is approx 7 years old, if that helps identifiying an approx joist size.
Thank you
Thank you