I would like to add another WC about 2m to the right of existing WC. The existing soil pipe has only one WC (coming out the wall straight into the soil pipe) and is a straight vertical cast iron 4 inch pipe with a vent at the roof. My plan is to go out the wall with the new WC and then go down and across to branch into the soil pipe. Therefore, a section below the existing WC joint must be cut away from the soil pipe and a branch inserted for the new WC. I do not wish to replace the cast iron system with plastic but would consider using plastic for the new section to the new WC. I have seen a connector Osma 4" Soil Waste Pipe | Fittings - OSMASOIL 4S106 GREY 4" S/S CONNECTOR TO CAST IRON SOCKET - R J Pryce - Plumbing, Builders Merchant & Ironmongery that will push into the lower section of cast iron and allow a plastic branch to be pushed in. But, how can the top of the plastic branch be connected to the cast iron above it? Presumably a second OSMA connector will not work upside down? I have seen ugly Fernco rubber couplers with jubilee clips but I would like something that matches the original cast iron and will last a very long time.