Connecting copper drain pipe to cast iron stack

[Greenman]

My friend just bought an old house here in the NE. When I went into his basement I just about passed out. Copper waste lines everywhere! I said dude scrap that stuff and it'll pay for that new A/C condenser you need.

I've never seen copper strapping like what's in the OP picture though. It has to be worth some good coin!

The "strapping" is actually a mount for the water stub outs. It's copper clad steel so you can solder the copper pipe to it.

 

[Greenman]

Holy cow! Why not?! Worried about toxic fumes if a house catches on fire (which would be eclipsed by the toxic fumes from the mattresses, any vinyl, couches, pillows, tons of fabrics, clothing, etc.)

I'm not sure about current codes in SF, but it used to be that cast iron or copper were the only allowed materials for DWV. No one uses PVC for waste around here, you can't even buy the proper fittings.

 

[Greenman]

Now I see a galvanized preforated strapping securing the copper drain pipe to the stud. I asked the plumber about this and he says the galvanized strapping won't stretch like copper and keeps it tight. I asked him about corrosion but he doesn't seem to think it's a big deal because there shouldn't be moisture inside the wall.

The inspector may or may not call him on it. The normal practice is to put a piece of tar paper between the strap and the pipe, or use copper clad strapping.

 

[DrPizza]

I'm not sure about current codes in SF, but it used to be that cast iron or copper were the only allowed materials for DWV. No one uses PVC for waste around here, you can't even buy the proper fittings.

That blows my mind. Oddly enough, my house has had the dwv system pieced together over the past 60 years; and I'm replacing it either this weekend or next. There's pvc, that black plastic pipe stuff, stainless steel in a few spots, etc. Recently, where the bathtub connects in, and where the washing machine is tied in, there are some leaks, due to disimilar materials/not quite agreeable dimensions. I was planning on replacing the entire dwv system in the house, right up to and including the toilet flanges with schedule 40 pvc. Shouldn't cost more than a few hundred in materials, and should last practically forever. It's probably 20% of the cost of copper, if that.

 

[crashtech]

I think the avoidance of PVC might have something to do with environmental considerations, being as it is more toxic and less recyclable than copper.

 

[Blain]

Cast iron drain line in walls and between floors is quiet.

 

[pcgeek11]

I think the avoidance of PVC might have something to do with environmental considerations, being as it is more toxic and less recyclable than copper.

The issue with PVC is also earthquakes and movement.

 

[paperfist]

The issue with PVC is also earthquakes and movement.

Cast is pretty brittle, would think it wouldn't last in severe movement situations. Maybe they hang it differently? Here it's usually buried in concrete in the basement.

 

[paperfist]

That blows my mind. Oddly enough, my house has had the dwv system pieced together over the past 60 years; and I'm replacing it either this weekend or next. There's pvc, that black plastic pipe stuff, stainless steel in a few spots, etc. Recently, where the bathtub connects in, and where the washing machine is tied in, there are some leaks, due to disimilar materials/not quite agreeable dimensions. I was planning on replacing the entire dwv system in the house, right up to and including the toilet flanges with schedule 40 pvc. Shouldn't cost more than a few hundred in materials, and should last practically forever. It's probably 20% of the cost of copper, if that.

Stainless steel waste lines? Now that's something I've never seen before. I wonder why they would that unless they wanted it to look pretty carrying s*^%

 

[IronWing]

Copper's at $2.40/lb. Don't quit your day job yet.

 

[IronWing]

Stainless steel waste lines? Now that's something I've never seen before. I wonder why they would that unless they wanted it to look pretty carrying s*^%

We used to have stainless steel all the way through in the lab plumbing. Turns out that the kind of stuff that required stainless steel piping for conveyance was exactly the kind of stuff that the city (not to mention EPA) didn't want in the sanitary sewer system. :biggrin: Now, they use the same crappy plumbing as everybody else.

 

[DrPizza]

Stainless steel waste lines? Now that's something I've never seen before. I wonder why they would that unless they wanted it to look pretty carrying s*^%

1 1/2" lines where there's an s trap for the bathtub coming into the basement. That's tied into that black crap; and doesn't have a proper connector. That's tied into PVC, again, without an ideal connection. It's about 15th on my list for today and tomorrow.

 

[Greenman]

That blows my mind. Oddly enough, my house has had the dwv system pieced together over the past 60 years; and I'm replacing it either this weekend or next. There's pvc, that black plastic pipe stuff, stainless steel in a few spots, etc. Recently, where the bathtub connects in, and where the washing machine is tied in, there are some leaks, due to disimilar materials/not quite agreeable dimensions. I was planning on replacing the entire dwv system in the house, right up to and including the toilet flanges with schedule 40 pvc. Shouldn't cost more than a few hundred in materials, and should last practically forever. It's probably 20% of the cost of copper, if that.

I've never seen a PVC DWV system, except on tv. We use ABS almost universally. Cast iron, copper, and galvanized, are in every house over 40 years old. I often use cast iron for vertical drops between floors for noise control.
You can still buy 3" copper DWV pipe in several supply houses. Though you don't want to drive down the street with it on your truck unless you have an armed guard.

 

[skyking]

I worked for a commercial plumbing outfit for several years. I had not seen a copper to cast iron setup like that. Thanks for sharing.
They had a wild plumbing failure on one of the jobs. It was a tenant improvement ( TI ) that was an italian restaurant. They had a pasta cooker that would dump gallons of near boiling water, and it would soften and deform the horizontal run of ABS!
They had to run cast iron for a long distance on the rework of that job.

 

[highland145]

Cast is pretty brittle, would think it wouldn't last in severe movement situations. Maybe they hang it differently? Here it's usually buried in concrete in the basement.

I doubt that there any plumbers, barring my bro, that know how to join cast iron pipe. S.C., btw.

oakum, anyone?

 

[Greenman]

I doubt that there any plumbers, barring my bro, that know how to join cast iron pipe. S.C., btw.

oakum, anyone?

No one uses lead and oakum anymore, though I do know how to do it. If you have to connect to an old piece of pipe at the hob, soil-seal is easier to use. Cutting it off and using a band is even better.

 

[highland145]

No one uses lead and oakum anymore, though I do know how to do it. If you have to connect to an old piece of pipe at the hob, soil-seal is easier to use. Cutting it off and using a band is even better.

No one? Times are a changing. Skills are lost.

Do you still have the tools?

 

[Greenman]

No one? Times are a changing. Skills are lost.

Do you still have the tools?

The tools are a big iron spoon, a torch, a piece of hemp rope, and a thing that looks like a cold chisel, I don't recall what it's called. You can pretty much improvise all of them. I don't think hubed pipe is even made anymore, there just isn't any need for it. Though I don't believe the bands we use now will last as long as the lead and oakum did, I've taken out some very old iron plumbing that worked perfectly.
As far as it being a lost skill, there are a lot of them gone. Wagon wheel builders, switch board operators, millwrights, the list goes on and on. It's progress, and sometimes that's a good thing.

 

[Tommy2000GT]

Silly question, it looks like everything is stubbed out for future connections. Seems kind of crazy to do a drain like that in copper just to cut it later.

What diameter is the copper drain anyway? Almost looks like 2"

Copper is soft, but I'd rather have copper on copper. Plus where's that pipe going on such a short run, so can't imagine there's much flex to it.

Looks like he has stainless screws going through the copper strapping too which is a corrosion problem. Also, just 1 screw holding the strap in the center?

Yep it stubbed out for later.

There are actually 2 screws holing the strap together and one at each end fastened to the studs.

 

[Tommy2000GT]

What the plumber has done is fine. I've removed brass to iron fittings that were 60 years old and never leaked a drop. They were corroded in place, but would have easily lasted another 30 years.

That sounds great, makes me less worried.

However in typical setups the inlet of the wye is facing the wall, wouldn't a brass straight trap arm normally be used? If so wouldn't the brass fitting act in my setup act the same way?

 

[Tommy2000GT]

The inspector may or may not call him on it. The normal practice is to put a piece of tar paper between the strap and the pipe, or use copper clad strapping.

The tar paper sounds like a great idea. I still have some around from installing the new roof.

 

[Greenman]

That sounds great, makes me less worried.

However in typical setups the inlet of the wye is facing the wall, wouldn't a brass straight trap arm normally be used? If so wouldn't the brass fitting act in my setup act the same way?

Yes it would.