Don't plan your waste before lifting your floor!
Not only is there the double thickness joist across the front of the breast but also an additional short joist into the side of the breast. The result: far too much woodwork and little space to have any confidence about being able to fix the waste to the tray, let alone then getting the pipe through all that lot.
So, undeterred, we've redesigned the en-suite and I actually think that the new design is better. It makes less of an impact on the bedroom we are snipping it out of. Plus, it gives more space for towelling down inside the bathroom. All a bit last minute but we had to have a design we could stick to before fitting the new soil pipe.
Fitting the soil pipe was a doodle. One big almost three metre run down to a right angled-bend pointing downwards at 45 degrees with an inspection opening. That goes straight into a 45-degree bend that levels off the pipe to a two-inch in sixty-fall, straight out of the side of the bay. The two bends both turn the run through 90-degrees and drop it under the joists into a bit of boxing in alongside the boxed in RSJ across the bay.
Sorted!
New en-suite floor plan
