cast iron soil to plastic fittings

[maax555]

Hi All, I am moving my toilet to the other side of the vertical soil pipe. Currently its a cast iron (looks to be 110mm) fitting. I am hoping that the section to the toilet can simply (with a bit of banging to loosen) be lifted out and a new plastic joint exiting to the right can be fitted. This will obviously overlap the rain water pipe from the roof. So here are my questions,
1) As the iron soil pipe is 110mm and the plastic fittings are the same is it possible to simply replace directly with a plastic fitting. If not whats the best way to achieve this.
2) Can i direct the water waste from bath and sink into the soil pipe, is that the think to do?
3) If the bath and sink can be directed into the soil pipe can i then fit some angles to the rainwater pipe to go over the new soil pipe which will run to the toilet?
4) I am thinking of doing this work myself, however depending on cost I may be happy to have a plumber do the work. The toilet would come out next to the lower waste pipe so new hole through needed etc. Does any one have a rough idea of cost for plumber/builder to do this?
Many thanks I am in the Newcastle Upon Tyne Area.

 

[Madrab]

Unfortunately not ... Cast iron doesn't loosen with a bit of banging, it cracks and breaks. It would need to be cut to requirements, noting where the pipe brackets are when cutting, as it's very heavy.

If you are moving the toilet to the right of the pipes, as you look at the picture, then I would be looking to rejig the whole arrangement. You wouldn't find it easy to pipe over the rainwater stack.

I would also want to check where the main stack and rainwater down pipe both feed into, with that arrangement it may be that you have separate foul and rainwater drains and if that's the case then the bath/basin shouldn't really be draining into that down pipe.

 

[Hugh Jaleak]

As above. I suspect the only option may be to remove the cast entirely from the junction upwards, and replace with plastic. Cutting the cast and grafting a plastic junction in may affect the support for the remaining cast pipework above, (hence why it is better to replace it for safety reasons.)

 

[maax555]

Thanks guys, so i should probably get a quote from a pro for this?

 

[dilalio]

Thanks guys, so i should probably get a quote from a pro for this?

Can you extend the branch to the wc on the inside, to the new location, and box it in?

Edit...
Mind you... You'll probably also have difficulty joining onto the cast internally and extending it over!