I have to replace a few pieces of cast iron soil pipe in the basement. (They're showing some pinhole leaks) I'm planning to use PVC if possible, but I'm not familiar with the transition from the plastic to the cast iron. I've seen things called "Fernco donuts"; is it as simple as using the correct size of one of these to fit into the hub of the cast iron, and pushing the pvc into it? Does it need sealant of any kind? Are they easy to assemble?
Thanks!