I have i down stairs bathroom with a cast pipe on the out side wall, which size i dont know, looks about 3",I want to add a bathroom up stairs, How do i connect the plastic pipe which will be 4" to the cast. ive read about some off you cutting the pipe and joining it, i would rather join at the joint that is there by cutting the old pipe out from the join and inserting something in there, is this the right way too do it,the joint in question is where the pipe starts to bend... help
i assume the 4" pipe is for the waste water from the toilet, i would suggest you send the new pipe into the sewer system direct if this not possible you may consider using a macerator,which is a device sits behind the toilet and mushes it all up then sends it out thru a small pipe ie 2" this can then be diverte to the 3" pipe or into the gulley point
interesting thought... and yes the 4" was for the waste, and the 3" is taking the waste away from the down stairs toilet, or is it 3&1/2".Is it an easy job to connect the 4" at the main drain under ground never seen what its like down there. :? :?
To join cast iron to plastic the easiest way is to cut the pipe in thye best possible position to be able to get to it easily as its not easy to cut. Then join cast to plastic with a rubber connector which you can see at this link.