dwv system and bath remodel

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by david101, Nov 17, 2008.

  1. david101

    david101 New Member

    Nov 17, 2008
    Quick background first - I am currently remodeling a 4 x 5 bathroom in the upstairs of my townhouse that was built in 1952. Since I had the bathroom gutted and the basement is unfinished, I have been looking at the dwv system and have noticed that the cast iron main stack/waste pipe is not set up the way I am used to seeing. It comes up from the basement at the exterior wall straight into the bathroom floor and then does a 90 degree turn and runs parallell to the floor and eventually does another 90 degree up through the opposite wall in the bath and goes up through the attic and out of the roof. I am used to seeing this pipe go straight from the basement and out of the house. Also, the toilet, sink, and bathtub are not vented individually. They all tie into this main line however and are all located within 3 feet of the line. The second thing is the the kitchen sink is individually vented in an odd way also. It is tied into a separate line that runs into the basement foundation (which I assume ties into the main line under the concrete) which has its own cleanout and everything else. The weird thing is that it goes into the drain through the floor and into the basement. In the basement, a separate vent line is tied into this line. The separate vent line goes up through the whole house and out of the other side of the roof. This line is a 2 inch line. Here are my questions -

    1. Do you recommend that I run a new system with pvc since the bath and basement are gutted? - I would avoid doing so just because of time restraints. I am a very capable handyman and do alot of household plumbing, but don't really feel like tackling this one right now, and it seems like everything is working just fine.

    2. If I keep the existing cast iron pipe and don't change it, is this setup (main line doing 2 90 degree turns) still an accepted way to vent the system?

    3. Is the kitchen sink properly vented? if not, would it be a good idea to install an air admittance valve in addition to the way it is vented?

    4. Because the tile floor in the bathroom was set on a 4 inch wet bed, now the flange is set too high for the new floor. It is also rusted and broke in certain areas. I was recommended to knock the flange out, and get all the lead and oakum out of the joint with a screwdriver, then replace it with a twist and set cast iron flange by oatey. Is this a good idea and will it last?

    Any help or advice is greatly appreciated as I respect your proffessional opinions. I apologize for the long background and hopefully I explained the situation appropriately. Thanks.
  2. patrick88

    patrick88 Plumber

    Sep 3, 2007
    Webster Ma.
    Leave the main drain as is. It is fine. The 2" kitchen line is fine also. The bathroom is stack vented from your description.
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  4. david101

    david101 New Member

    Nov 17, 2008
    thank you for the reply. how do you feel about the twist and set flange being used to replace the old one?
  5. hj

    hj Moderator & Master Plumber Staff Member

    Aug 31, 2004
    Cave Creek, Arizona

    I am a plumber, therefore, I have no problem doing it the correct way with a new leak/oakum flange. I NEVER use the twist and set flange, or anything like it.

    Pouring a Lead Joint
    Last edited by a moderator: Nov 22, 2008
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