View Full Version : Replacing Cast Iron Waste in Kitchen Wall

10-15-2009, 06:10 PM
My house is 1920's and I'm currently doing kitchen renovation. Since I have the kitchen gutted and the cast iron waste exposed, I'm thinking it's a good idea to replace it with PVC...

If I do...when I make the cuts from the kitchen to remove that section what prevents the section above from dropping down? Even if it shifted a little down this will cause a leak in the roof because this is where it is vented.

Anything special I should do? Any precautions? Suggestions?


10-15-2009, 06:23 PM
In some places it's not allowed to have pvc with CI above it bearing down...CI is very heavy!

Is there any plumbing above this draining into that line? Shouldn't be if it is a vent.

If you are going to remove it, probably best to go all the way through the roof.

Note, CI vents could last a very long time since there's not normally much of anything going through them except air. It could be in fine shape. Now, when it is actually a drain could be worn out, depending on use and local conditions.

10-16-2009, 01:36 AM
There is plumbing above the section I want to remove, the 2nd floor bathroom. I'll call the local township and ask them the code regarding this. Maybe I can get a plumber in the check and see if this part of the waste is okay...thanks.

10-17-2009, 06:59 PM
Put a riser clamp around the pipe and use backing to support the clamp.

I found a picture of what im suggesting, i would put in better backing then that though, it looks pretty flimsy...


The coupling should have a metal band around it to keep the pipes from shifting
Added by Terry

10-20-2009, 06:15 AM
Thank you for this tip; however, my CI pipe has joists running along both sides, barely room for a sawzall. I am alowed by code to replace the CI with PVC. Something to think about...