Please help, urgent! First post here, hoping someone can advise.
We're planning a new WC in a garage, attached simplified sketch shows the plan. A builder we've been talking to has suggested a 110mm connection leading directly from the WC through the slab, then changing direction slightly to...
Can the foul waste from a WC go on the same underground drain as an open gully? Basically the the gully would drain directly into the foul waste pipe? Hope the sketch below shows what I mean. Black is existing, blue is new.
I can't send the WC drains to the SVP because there isnt enough fall...