Plumbing

Could switching a toilet & bath/shower next door cause backflow in my toilet?

Anonymous user 23/02/2024 - 2.51 PM

I live in one of the bottom flats of a purpose built block of 4 studio flats - 2 up, 2 down. The owner of the downstairs flat next door has swapped the original positions of his bath and his toilet & replaced the bath with a shower. The work was done by a soldier friend of his. Ever since, I've suffered back flow in my toilet. The owner goes away for days on end & I have no problems till he comes back, then the backflow appears again. I've read that toilet waste pipes need to be a lot wider than bath/shower waste pipes. If these were never swapped as well, could this be what's causing the problem? Have had DynoRod, MetroRod etc checking everything externally through the outside drains & they are baffled as to what's causing this. Any suggestions welcome.