Removing old cast iron plumbing drain stack -- ideas?

[kendallf]

I'm in the middle of demolishing the bathroom in the house we just bought.  I'm going to replace the old cast iron plumbing with PVC, including the main vent/drain stack.  I'm going to have to remove it from the wall in sections, it looks like.  I can use a sawzall to cut it, probably..but that sounds laborious.

Any better ideas?  Pics here:

http://www.flickr.com/photos/26276815@N07/sets/72157632504633648/

[Nords]

I'm going to replace the old cast iron plumbing with PVC, including the main vent/drain stack.

First let me ask the easy question-- does it have to be replaced?

Cast iron is acoustically "dead" compared to PVC, and it doesn't transmit as much noise/vibration.  In other words the whole house won't know when you've finished reading the sports section and pulled the flush lever, or started the shower.

This YouTube video suggests four different ways:  hacksaw, reciprocating saw, grinder, and old school.
http://www.youtube.com/watch?v=Zei2c_moHIQ

[James]

I spent a decent amount of time working with cast iron, definitely agree with Nords that it shouldn't be replaced unless you absolutely need to.


Sawzall is definitely best if you are going to need to connect to it at a lower spot, any other form of breaking it out can lead to breaking it at the spot you still need it.  There are breakers you can rent that wrap around the pip and apply pressure until it snaps.  These are quick and easy, but if you only need to make a cut or two then it's probably overkill, just take your time with a metal blade on the sawzall.


If absolutely all of the cast iron is going, nothing wrong with a sledgehammer. (eyes protected of course)

[kendallf]

The drain/stack needs to be replaced; there are multiple leaking joints under the house, and inside there were rubber couplings on the sink and tub overflow drains, along with a patchwork of PVC and original galvanized supply line.  A number of lines added on over the years snake haphazardly under the house and do not meet code; the home inspector told me that these would flunk the insurance four point inspection.

Given all of this, I'm just going to cut the main drain near where it exits from under the house, put new PVC drain/vent piping in, and new PEX supply lines. 

Thanks for the suggestions; we also met a couple tonight who own several houses in the neighborhood, and his suggestion was also to get in there with the Sawzall, after first strapping the upper part of the vent in the attic so it won't fall.

I'll post more progress pics in a few days.  :-)

[Mountainman75]

Find a local tool rental store and rent a "soil pipe cutter".
Works particularly well on the larger cast iron drains and sewer lines.

[kendallf]

Thanks for the tip!  I updated my thread in Real Estate but forgot to update here. 

I got some carbide Sawzall blades, and made a neat cut near the clean out where the pipe exits the house, and one in the main soil stack.  Then I got the sledge out and broke the rest of the piping up.  It really wasn't that bad.  I did some framing work after that, and next week I'll start replumbing the whole house. 

[Mountainman75]

My next re-plumb job will be with all the supply lines in PEX. $75 for the crimper, but it saves you hours (or days) of time during the install, especially DIY.

Cheapest place I get PEX and fittings is from these dudes: http://www.blueridgecompany.com/
I buy 1000' rolls, and use the offcuts for side jobs, or manifold runs on hydronic in-floor heat setups.