I am replacing a plastic (fiberglass?) shower pan with a new one. I have the existing pan free from the walls and subfloor, but it is still being held in place by the drain flange (I did remove the strainer!). The flange appears to be cast iron (it is very rusted inside) and is about 4 inches long and then it connects to black PVC below that. I would like to remove the cast iron part without damaging the PVC. What is the best way to do that? I drilled a couple of holes through the shower pan itself, but it would be time consuming to drill enough holes to free the pan from the drain by this method.

Thanks for your help.

Cast iron is very brittle and will break easily. To removethe shower base I would take a hammer and whack the flange till it breaks. You may then removethe base and pick out the rest of the cast iron drain. Good luck, Tom

Thanks speedball1. I used a chisel and mini-sledge (I'm a geologist!) to remove the tile walls of the original shower so they should work perfectly for the flange. I'll have more questions if I have to extend the PVC riser after I remove the cast iron!

Thanks for the quick reply.