Hi,
We have an internal cast iron soil stack in our house, as per 'existing' image. The red circle shows where the collar of the clay pipe has been damaged and is leaking slightly. The stack finishes behind the toilet, so I assume it has some sort of durgo valve.
We're renovating the kitchen, and would gain some space by moving the stack outside. We'd also be changing the sink to under the window so the waste pipe would probably need to be reconnected 90 degrees around.
We're also thinking of a loft extension further down the line, so a full external stack may be easier to connect a new toilet and shower to.
Questions:
1. Is it fine to move the stack to the outside? it will run alongside an existing gutter downpipe. I'd make it a full height stack extending above the eaves. (red)
2. Is it ok to extend the rear pipe of the toilet approx 400mm to reach the new external stack?
3. Should the external stack route back inside at the bottom (yellow route on pic) , and be fitted into the existing indoor clay pipe?
Or should I dig out between the manhole and the house, and install a new underground pipe that comes to the surface outside?
We're having some building work done so it would be nice to tie it in, and will also be having building regs inspectors visiting.
thanks for your help!