On Aug 15, 11:54 pm, John Rumm wrote:

I would not take that as gospel....

The pipe you want to attach to, what is it a soil pipe or a rainwater pipe?

If the latter then you would not be able to tee into it unless you also
have a combined surface and foul water sewer.

There is nothing to stop you mixing plastic with CI in this way as far
as I am aware either.

Hi John. I spoke to a guy at the council building control department,
and he said that the new branch would need to be cast iron, but the
drain pipe that feeds into this branch could be 50mm plastic. So no
strap-on-bossage allowed.

Also I discovered that because I'm not installing the kitchen in a
room that already had a kitchen in it, all the work would need a
building warrant - and I've already started the work, including
putting in some sockets. I hate the world!