Cast iron soil stack replacement

[messimagician]

The main cast iron soil stack runs up the wall with a single T that goes off to the toilet, the pipe then goes through the garage roof and vents about a meter above the roof line.

The bath and sink waste go to a smaller separate soil pipe which is about the same size as the rain water downpipe but I would like to join both of these to the main stack instead and have the smaller soil pipe removed, would this involve major works with the drain or can this be just filled in where the pipe was?


Also can you mix solvent weld with push fit on the main stack or do you have to pick one or the other? Which is the best to use

 

[Rckape]

The smaller soil pipe you mention will be rainwater down pipe with a hopper on top and may join via a gully to your sewer or it may head off to a soakaway.

I'd advise against trying to connect plastic of either type into cast iron. If your dead set on removing the hopper and down pipe then the best bet would be to replace the whole cast iron stack with a new plastic one.