Are you sure you have a shallow waste trap? I cannot see how a bath could
be mounted so low as to need a cut in the floor with that fitted.

Steve

Yes, it is a shallow trap. The hole in the floor was already there
from a bodge of a previous plumber. I think my option will be to core
drill a new hole lower down the wall so that it all drains off rather
than being forced up and out of the current pipe.

We had a leak from the trap yesterday, where I found the trap wasn't
sealed properly due to the way the pipes had been laid (should have
done the job myself!), and no PTFE tape on the waste connector!
Getting it to pieces was a mission as the whole of the pipework was
full of water (as you would expect).

The HepVo traps, are there any limitations on where they can be placed
along the waste, e.g. would I need to elbow off the bath waste then
immediately insert the HepVo trap?

Cheers

Dave