What are these pipes?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Reno_Now, May 29, 2008.

  1. Reno_Now

    Reno_Now New Member

    Messages:
    2
    We are looking at a house that we might buy, a 100 year old solid stone home. On both sides of the house, there are these pipes coming out of the ground, close to the house. They are about 2-3 feet tall and are candy-cane shaped.

    I'm thinking they are venting pipes of some sort. The house has natural gas (no oil tanks as far as we're aware) and is hooked up to the city sewers and water (but might not have been in the past). Someone has suggested that they may be air inlets for a whole house trap? I just don't know why there'd be three of them if that's the case.

    One one side of the house, there is one of them (see first pic below), on the other side there are two of them (sorry for the obscured pic). The house is quite wide, probably 60' wide, and the basement is above ground on the sides and back of the house (walk-out). Thanks!

    [​IMG]
    [​IMG]
  2. Gary Slusser

    Gary Slusser That's all folks!

    The first thing that comes to mind is radon mitigation. But it could be they are sewer vents but... without traps, you'd be able to smell sewer odors.
  3. Cass

    Cass Plumber

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    Possibly a vent for a whole house trap.
  4. Gary Swart

    Gary Swart In the Trades

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    Given the age of the house and the appearance of the pipes, I would side with Cass on this.
  5. Redwood

    Redwood Master Plumber

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    My guess id that you have a couple of separate waste lines leaving the biulding and each one has a house trap on it.

    House Trap
    [​IMG]

    They are commonly configured like the drawing below
    [​IMG]
  6. jimbo

    jimbo Plumber

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    The radon idea occurred to me since there are so many. Find out if radon is an issue in your area. Then find the crustiest, oldest plumber you can find. He will be familiar with construction methods from the time frame your house was built. He will know if house traps and outside vents were commonly done.
  7. Redwood

    Redwood Master Plumber

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    Somehow I don't think Radon was an issue that concerned anyone when those vents were installed...
  8. oil vent>>>???

    radon is totally off base,


    i would guess something to do with vents for oil tanks...
    Last edited: May 31, 2008
  9. jimbo

    jimbo Plumber

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    I guess the thing that throws me is why 3??
  10. Bob NH

    Bob NH In the Trades

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    They could be vents for French drains.
  11. gear junkie

    gear junkie Plumber

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    Virginia Beach, IPC country
    They're vents for your gas line.
  12. Reno_Now

    Reno_Now New Member

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    How can they be vents for a gas line??

    I don't think there are any buried oil tanks, the house has an above ground basement and is built on bedrock, so digging for an oil tank (or 3) would have been difficult.

    I didn't think French drains needed venting. If so, then they could be for french drains, as the house is just slightly above a flood plain and the land it sits on is on the waterfront.

    The house is 100 years old, so it could be that they are vents for a whole house trap, or possibly two whole house traps. The house is wide (60') with plumbing on both sides of the house, so maybe there are two city sewer connections, or potentially one could have been for an older septic system.

    I guess we'll have to wait and see what the home inspector says before we make an offer. We were thinking of having one person listen at the vents while another flushes various toilets in the house to see if we can hear water rushing. That might give us some more clues.
  13. jimbo

    jimbo Plumber

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    Bedrock is where the radon problem shows itself.....but I understand these pipes appear to predate the period when the radon problem became known about.
  14. srdenny

    srdenny Plumbing Contractor

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    SF Peninsula
    Stick your ear in one of them while someone else flushes the toilet. If you hear any noises, or feel a rush of air, then they are probably connected to your sewer line. Radon, my arse.
  15. TMB9862

    TMB9862 New Member

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    Just about every commercial building here has a setup like that for the house trap vent. It's quite possible you ended up with two house traps for one reason or another over the past 100 years. Can you see any house traps in the basement?
  16. gardner

    gardner DIY Senior Member

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    Location:
    Ontario
    The OP says there are THREE of these (not two). I can't imagine there being THREE separate house traps or that any sort of sanitary drain vent would be placed at this level.

    My bet is that they are connected to the storm drains somehow.
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