I have a rear gully which is leaking and I think is responsible for the damp on an internal spine wall.

I need to dig out the gully and want to move it to the right so it is a bit more away from that corner.

This house was converted into flats in 1965 so I think the drain set up was changed then. Originally there was a door into the cellar next to the old clay pipe.

Question: what coupling do I use to connect into the clay pipe. I want to connect when it is in the vertical position and then I will add backwards in plastic. I will probably do the last leg of the downpipe in plastic as well and angle it at 45 degrees to the right.

My other worry is, could the soil pipe wedged in the corner also connect into this gully and so use the large clay pipe? Or will that go all the way to the bottom and hit the floor with its own pipe?

Ps. I am trying to load a photo to help you, but struggling

photo showing how close the soil stack is to this down pipe.

Do they both go into this clay pipe ?

The leak is happening on the horizontal bit going from the clay bend into the main downpipe, back towards the gully. So a distance of 300mm approx. I think the gully chamber maybe cracked.

I'm hoping to break it out tomorrow.

Can you get a photo/video of the underside.

At that age likely to be a combined drainage system, I'd have thought, so likely to be connected to the soil pipe.

Get someone to flush the toilet and see what you can hear/feel?

Yes the horizontal section feeding into the gully is leaking. Not fully sure if it is the bottom of the gully

My next test is to flush the toilet and see if water leaks. I have put the hose into the gully and it is leaking from underneath.

But it all means the soil bends to the right and then goes through a gully and then hits that 90 bend to turn down and head underground.

The soil is all concreted in by the wall set up holding up the back door stairs.

Got it out today and it is a separate system above ground to the soil pipe, which makes my life easier.

Any option to route the down pipe along the wall and on to the garden/soakaways to the left of the pictures? Save messing with the gulley and keep surface water out of the sewage system.