Putting PVC to cast iron tub and pipe
 

Hey guys I'm putting back together my house I just got and im putting the original cast iron tub back in and the problem I ran into is I have cast iron piping that runs from under the house by about maybe 15ft to new pvc. My question is, is it ok to join pvc to a cast iron tub and then join it to the existing cast iron piping? If so how do I do this. Im not a plumber and well.. this is the only thing holding me up lol. Thanks!

If I'm understanding right all that would be fine.Your tub is connected by a waste and overflow,don't forget to put a p-trap in.To connect the PVC to cast iron pipe use a fernco(rubber coupling)

Is there a vent pipe heading for the roof?

Pictures of what you have will get you the best answers---otherwise--do your best to describe what's there.