Just read project on new soil pipe: https://www.diydoctor.org.uk/projects/soilandvent.htm and adaptor into ground,but I am not changing soil pipe .
My soil pipe I think is possibly cast iron is ok but after some work on lowering the ground around the back of my house ( built up over the years and is to high) the clay pipe in ground, lip has half broken off .
Is there a connector for this job ?