Replacing Copper DWV with PVC

[gedmeyer]

I have 3 stacks in my basement that are 3" copper dwv into a CI wye, as shown in the picture.

All stacks will receive some plumbing changes that I will use PVC for. What's the most sensible method and location to switch to PVC?

Keep a 12" copper stub out of the CI wye and then use a shielded fernco to switch to PVC? Or Remove the Cu entirely?

Tim

 

[Reach4]

I would not replace the copper except where necessary to make your functional plumbing changes. Is there something that makes you distrust the copper?

You can use banded couplers to connect PVC to copper. While Fernco makes banded couplers, when people say "Fernco coupling" they are usually referring to the unbanded ones that came first. Mission became associated with the banded couplers. They now both make both kinds.

https://www.fernco.com/plumbing/shielded-couplings/proflex-couplings
http://www.missionrubber.com/Products/BandSealCouplings.php

It looks to me as if you would want Fernco 3007-33 or Mission PK-33 for 3 inch. But they each have the smaller ones too.

 

[Sponsor]

 

[gedmeyer]

I would not replace the copper except where necessary to make your functional plumbing changes. Is there something that makes you distrust the copper?

You can use banded couplers to connect PVC to copper. While Fernco makes banded couplers, when people say "Fernco coupling" they are usually referring to the unbanded ones that came first. Mission became associated with the banded couplers. They now both make both kinds.

https://www.fernco.com/plumbing/shielded-couplings/proflex-couplings
http://www.missionrubber.com/Products/BandSealCouplings.php

I'm doing significant remodeling, so wholesale switching to plastic might be easier and cleaner. All drains and vents are currently exposed as well. There are many issues I'm correcting -- incorrect fittings, too little pipe slope, venting to the attic, etc.

I wasn't sure it is was worth trying to remove the copper from the CI. I'm guessing not and using a mission fitting a few feet up from the floor is the most practical.

 

[hj]

Any one who would use copper for DWV would usually be a competent tradesman, so I question whether your assessment of "incorrect fittings, too little slope, bad venting" is actual or just the perception of a "non plumber".

 

[gedmeyer]

Any one who would use copper for DWV would usually be a competent tradesman, so I question whether your assessment of "incorrect fittings, too little slope, bad venting" is actual or just the perception of a "non plumber".

The house is 40 years old. I don't know who installed what. I'm a non plumber, but certain things are obvious and I do my home work.

The vents to the attic are easy to see as are the low slope branches in the basement. Also, the washer drain drops 8ish feet (through the floor), then goes horizontal for 4 feet, then drops 3 more feet, then to a trap that is an inch from the connection to the vertical stack. The stack is vented, but there is a lav and and WC drain tied in above.

The house is pretty good structurally, but the mechanicals have some issues. I also have changes required due to my remodeling.

Would you say leaving a copper "stub" from the CI is a good choice for connecting my PVC to? This would be easy for 2 of the 3 stacks. The last one has a tee fitting right above the CI connection. (This fitting is from the washer, described above, and needs to be removed.)

Tim

 

[gedmeyer]

Any idea how the copper is attached to the cast iron? Is it a threaded connection?

 

[Terry]

That is a lead and oakum connection. They put the rope down first, and then pour hot lead over the top of that. Then tools that spread the lead to make a tight seal.
Sometimes I will drill out the lead and peel it out to remove the fitting. They do make rubber sleeves that insert into the hub now. Or you could cut the copper and use a copper by plastic Mission coupling.

 

[gedmeyer]

That is a lead and oakum connection. They put the rope down first, and then pour hot lead over the top of that. Then tools that spread the lead to make a tight seal.
Sometimes I will drill out the lead and peel it out to remove the fitting. They do make rubber sleeves that insert into the hub now. Or you could cut the copper and use a copper by plastic Mission coupling.

Thanks. I think the mission coupling is the least risky for me to tackle!

The cleanout side of the Wye was never installed... Just get a rubber plug or donut to pvc w/ a cleanout?

 

[Reach4]

Make sure of your pipe supports before cutting the copper.

 

[Plumber69]

Are you able to get that clean out off

 

[MKS]

You may want to evaluate the condition of the copper for thinnimg on the surfaces the waste travels. In some cases it can erode and leak.

 

[Jadnashua]

The copper you remove will have a significant recycling monetary value, but be prepared to provide info that you didn't steal it from a building! YOu might want to call them first to see what they want as proof. It may just be signing an affidavit and showing some identification. Lots of people steal copper from buildings.