I've just installed a new bathroom and added a shower cubicle to where the airing cupboard used to be.
The waste pipe from the raised 'easy plumb' shower tray runs along two walls before joining the main soil pipe. Along its run it is joined by the waste from the wash basin and, finally, just prior to the soil pipe, the waste from the bath.
I'm finding that when the bath is emptying, the water cannot drain away into the soil pipe fast enough and there is a some 'backing up' of the water to the shower tray where there is a slight rise of water around the drain. It's not serious and there is no question of the shower tray filling up - but I'd rather it didn't happen at all.
I'm aware that HepVo valves are designed to allow the flow of water in one direction and then to seal and prevent 'nasty nifs' from coming back up the pipe. I wonder whether such a valve would also work in preventing the bath water from reaching back to the shower tray - or is a flood of water trying to go the wrong way likely to damage the HepVo?
Any views anyone?