How to join a cast iron rough-in drain to shower drain?
Hello. This is my first post. I have done some searching and not finding a way to do this. I have a cast iron rough in drain that I would like to join to a new shower drain. I have already taken out a rough mortar bed that was underneath a prefab shower pan. I will be building a new mortar bed for a new pan so that I can tile the shower. I would like to leave the existing cast iron drain in place and don't want to have to break up the concrete and replace it... How do I connect my new drain to the cast iron drain pipe?
Thanks to any and all for any help!
http://www.draggon.com/pics/roughin.jpg
http://www.draggon.com/pics/showerdrain.jpg