The new bath has a centre drainhole, and we have a popup waste supplied with the bath. The trap is a slightly odd looking flat rectangular affair designed to fit between the underside of the bath and the floorboards. We need to use it because the popup waste mechanism is integral to it.
Ok, that's fine, but it was my understanding that a trap on a pipe connected to the soil stack should have a 50mm water depth, and I'm pretty sure this doesn't. Need to have another look at it.. Is that correct?
If so, I reckon I could fit a running trap, or a P trap , in the pipe underneath the bath before it goes down under the floorboards (for a run parallel to the joists to the external wall.
Thanks