Soil pipe annealing and sealing of a iron barrel pipe to Plastic pipe on toilet basin

[Andrave2]

Hi to all on not DIY forums I moved into a flat in W,yorks in June and noticed I were getting slugs in my flat bathroom and W.C. and for weeks I wondered how the slugs were getting inside the bathroom just over a week a so ago.
I noticed a gap in my internal sewer pipe where the iron barrel stack pipe has the narrower plastic pipe plumbed in and just been filled in with cement as the pipes are different circumfrances the iron barrel 4 inch been imperial and the later plastic pipe 85mm metric size. The cement ont the pipe has eroded away and the iron pipe quite corroded and thus left a quarter inch gap between the 2 pipes were they are joined could anyone help on how to reseal the gap on the pipe joint?

 

[Wayners]

Can you add a picture

 

[Andrave2]

Can you add a picture

Yes here is one of where the hole is on the joint of the pipe on my basin if you need a left hand shot of the pipe Wayners: can do that also

 

[Wayners]

That's really needs replacing with plastic soil pipe insert.
Depends on pipe condition but I suspect it all needs replacing with plastic.

What is your plan. Temporary fix or look to replace?

 

[ree]

OP,
The quickest, simplest & cheapest method of dealing with what you have is to remove the WC up & away from the soil pipe. Examine the flooring where the pan was for water damage.
Remove the pan connector from the spigot, and then thoroughly clean around the soil pipe opening.
The CI soil pipe might be cracked or perished so take well lighted pics from each side of the clean soil pipe?
Are you on the ground floor?