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D-W-V vent stack pipe types

My circa 1905 home's three vent stacks that vent toilets are galvanized steel. The two vent stacks that do not vent toilets are cast iron. I assume from this that the galvanized was used for such purpose because it is more impervious to methane gas. Is this true? Does residential home construction use galvanized and cast iron in this manner today when plastic is not used?


  • Eric_32
    Eric_32 Member Posts: 267
    Cast iron, galvanized, &

    Copper and brass piping have all been used as DWV materials before plastic.

    I don't think the the installer was worried about the piping being inpervious to methane. I bet it either came down to cost or what he had on hand. Probably cost.

    All vents that I've removed over the years, either cast or galvanized are still like new. Drainage pipe on the other hand is a different story.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    Some codes required the use of galvanized pipe..

    I think the SCBO use to require the use of galvy pipe. I know they did if it was exposed to the elements outside (fuel lines), but not sure about the DWV. As Eric said, it was probably more a matter of what was on hand and was acceptable to the code and cheap.

    Todays HOMES are typically either plastic throughout, or in some custom situations, cast iron for drain (noise control) and plastic for venting.

    Commercial is a different beast.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • icesailor
    icesailor Member Posts: 7,265
    DWV Vent Stacks

    Galvanized steel pipe is acceptable for waste and vent piping. It was used for waste and vent piping under 2". They did not make 1 1/2 " CI Caulked soil pipe. When No-Hub came in in the '60's and 70's, 1 1/2" NH pipe was used but not that popular.

    Old  houses of your vintage have it on trap arms and tub wastes. The other choice was wiped lead joints.

    But, I ask, these galvanized vents, are they galvanized rain water conductor pipes that come out of the wall and connect to the back of old two piece toilets? Or, are the pipes there and no toilet connections to the toilets because they have been replaced?

    High end houses of your era had a horn on the back of the bowl that you connected a conductor pipe to th get rid of the stinkies when one did a big stinky.  
  • jonny88
    jonny88 Member Posts: 1,139
    galvanize pipe

    in nyc they used we still come across galvanize pipe on domestic water lines in the larger should see the conditions of theses pipes when we cut them for waste galvanize will rust and catch debris causing stoppages,then when the handyman snakes the line he usually puts the snake through the pipe,it becomes so britttle.especially on the threads.we replace water lines with copper,waste with no hub pipe(its quiet) and when we have gone to the trouble of that we will cut the galvanize vent out to and replace .you can use plastic though,some prefer it,its cheaper and easier to install for a home owner,but i believe cast iron is a more professional choice,only my opinion.
  • Schvenzlerman
    Schvenzlerman Member Posts: 39
    1. Here's the home's original plumbing scheme:

    2. 1. Galvanized steel pipe fed water to fixtures other than toilets. This pipe is totally filled with crud;
    3. 2. Large copper tub in attic fed water to toilet bowls via SEPARATE 2" galvanized steel pipe system. This tub was not filled from rain water;
    4. 3. Three 4" cast iron soil stacks;
    5. 4.Four 2" galvanized steel vent stacks;
    6. 5. One 2" cast iron vent stack (no toilets vented from this stack);
    7. 6. Vent stacks' horizontal runs to fixtures are galvanized steel ; and

    8. 7. Lead traps
    In a few instances, the galvanized vent pipe transitions to (is welded to) brass and then to lead in order to get custom sweeps of and connections to the pipe. That sort of lead pipe use was really an art form from my non-plumber perspective.

    1. In fact, that raises another question. In one case, I have to join a piece of no-hub 2" cast iron pipe to lead of same diameter. No-hub couplings are torqued at 60 inch pounds. I assume that pressure would collapse the lead pipe. Any thoughts?y

  • Eric_32
    Eric_32 Member Posts: 267
    edited February 2011

  • rlaggren
    rlaggren Member Posts: 160
    What's the CI/Lead connection carrying?

    Air or water? Do you _have_ to make that connection or can you replace the lead?  How much lead pipe do you have to work with before it disappears into a wall?

    The right way would be to wipe a connection from the lead to a 2" brass ferrule, then connect to that. Just about impossible to find anybody who has that experience, though. Last guy I knew had worked regular with lead joints retired 20 years ago.

    disclaimer - I'm a plumber, not a heating pro.
  • Schvenzlerman
    Schvenzlerman Member Posts: 39
    cast iron-to-lead connection?

    The lead carries water. Replacing the lead would be quite difficult due to a very constricted area. 
  • icesailor
    icesailor Member Posts: 7,265
    Lead Wiped Joints:

    If you have lead wiped waste pipe joints, that building is older than dirt.

    In MY experience, if you have cracked soil pipes, and lead wiped joints, you have leaking lead joints. And if you have lead closet bends, with the toilets screwed to the floor with closet screws, you will need to replace them with brass wiping flanges where the flange is soldered to the lead. Don't even TRY to attempt to fix those. Just put the wiping flanges on. It's an art form.

    If they used brass lead wiping sleeves, you just melt the solder off and use a no-hub coupling to connect PVC or whatever is allowed. It's not a big deal.

    You sound like a non-pro rookie. You will find that the 4" soil pipe is slightly smaller than the new pipe. If you use a No-Hub coupling to join old with new, you need to use a 4 band NH coupling, cut a rubber sleeve so you have two. That means cutting the shoulder out of one sleeve, and using it as a filler/spacer to make the SS shell coupling fit properly. You can roll the sleeve back and slide the new piece in place, roll the sleeve over the pipe, clamp the pipe and be done with it. Some use Fernco Couplings but they rot out after 5 years and you then have a leak.

    I do this all the time. Do it right or get someone else to do it who has experience. Be careful you don't end up with something that could be showcased in the HGTV show, Holmes On Homes.

    OBTW, only the pipes are cracked. Not the fittings.
  • jonny88
    jonny88 Member Posts: 1,139

    they make another coupling to go from the old cast iron to the new cast iron.for 3"it is a cp33 ,4" a cp44 etc,one side of the rubber is slightly larger than the other side to accomodate the old cast iron.they work great,icesailors way works fine to,actually did it his way today as we had an emergency and had no cp couplings in the truck.
  • icesailor
    icesailor Member Posts: 7,265

    Where I work, I use what I can use. In the beginning, way back when I always used NH couplings. Fernco came along. I have used them but I found old ones with the rubber rotted out and split through. I like the NH couplings because the SS shell covers all and holds it all together. You can't use Clamp-All's because the middle of the sleeve is fatter than the ends.

    When the NH couplings first came out, the "Powers" claimed they would be the ruination of plumbing, that a child with a 5/16th nut driver could dismantle an entire plumbing system. My old boss said it was a wonderful repair kit.

    My old late boss was right. It's a wonderful repair kit.
  • jonny88
    jonny88 Member Posts: 1,139

    you got a wealth of info when it comes to heating and now plumbing just shows how much there is to learn in this trade.personally whether you know it or not you have helped me out a few times during the heating is great that you come on here and share that info.thanks for all your help.
  • icesailor
    icesailor Member Posts: 7,265
    Stack Pipes:

    Thanks for the kind words.

    When you are faced with a situation and you ask around, and you are looked like you have three heads, it becomes time to innovate and improvise.
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