Replacing Cast Iron Soil Stack. (pictures included) Help me please!

[slindsey3000]

Hi,

I have a cast iron soil stack that is cracked badly a length of about

5 feet. The crack goes from the top of one section to the bottom of that section. The other sections seem fine above and below.

I would like to replace with PVC. It is a straight shot from the basement up through the first floor and to the second story bathroom. Ther are no other conections on first floor or basement.

The problem is BELOW where the toilet / bathtub / and bathroom sink meet at the stack, so I just have to replace a strait length of pipe down to the basement.

1. How do I loosen the conncetions between two pieces of cast iron so I can take out this damaged section and the 2 sections below it. Heat the lead and Oakum and twist the sections apart?? Will that get the pipe sections seperated? How is it best done?

1. How do I reconnect PVC to this cast iron piece.

2. Do I need to support it from above? Can I grab ahold of the vent on the roof with a clamp and thus support the stack above the cut?

Click here for pictures:

Any other advice!?? Thanks guys!!!

[Nexus7]

Looks like you have full access to the entire cracked length of the pipe. Can you check with a plumber about some epoxy weld? Because the stack is not under pressure, so a decent weld or that old-style lead thing could save you from having to open the mess and putting a new pipe through floors.

[Howard]

Seriously consider replacing with cast iron NOT PVC. The pipe appears to be in a living area wall. PVC is much noisier than cast iron (ci absorbs noise).

The simpliest way is to get a soil pipe cutter and cut above and below the damaged pipe , removing both the hubs. Then use compression type collars to attach both pieces with a new length of cast iron. You must also support the stack directly above the cut with one or more stack clamps. Lead and oakum joints cannot carry a downward force so you can't let the stack hang from the roof!

This is a job that a plumber with the right tools can do reasonably quickly.