Laundry/Utility Sink venting in basement

Discussion in 'Canadian Plumbing Code Questions' started by BrianK, Jun 16, 2012.

  1. BrianK

    BrianK New Member

    Messages:
    26
    Location:
    Calgary, Alberta, Canada
    I installed a laundry/utility type sink in my basement - you know the white plastic ~2'*2'*2' type sink. The drain is about 6 feet away from the main 4" house drain which I tied into - and there was no vent line nearby. I used a 1/1/2" ABS drain line and trap below the sink outlet. Since there wasn't a vent line nearby I installed the drain without a vent but did consider using one of those vacuum breaker type things. The guy at Home Depot (who said he was a plumber) said it may or may not work properly and to try it without the vent or vacuum breaker first - which i did and it works just fine. I fill the sink up completely and it drains quickly with no problem at all and leaves water in the trap when it finishes draining as it should.

    My question is - when I go to sell the house - is a home inspector going to fail this installation because it doesn't have a vent. (Installation in Canada).
    Thanks for your comments.
  2. kreemoweet

    kreemoweet New Member

    Messages:
    371
    Location:
    Seattle. WA
    Home inspectors do not and can not "fail" anything, but it IS their job to note any existing deficiencies, problems, building code violations, etc., so one would
    presume that the alert H.I. would mention it.
  3. mikeplummer

    mikeplummer Plumber

    Messages:
    190
    Location:
    Ontario, Canada
    if you ever watch Holmes you might notice that a lot of home inspectors wouldn`t even catch this. secondly they have no authority to `fail` plumbing installations.
    the sink will drain fine as long as the drain is has no blockage, the only issue cause by no vent would be trap seal loss created by backpressure potentially from the drain you tied into, or self siphonage from the sink itself. this would result in sewer gas coming back through the drain if the trap seal loss is enough to let air pass.
    it would be easy to install a `T` in this line with an auto ~cheater~ vent extended above flood level rim of sink
  4. BrianK

    BrianK New Member

    Messages:
    26
    Location:
    Calgary, Alberta, Canada
    Thanks Mike and Kree. I won't point out my 'deficiency' to the 'qualified' home inspectors as it does seem to work properly. I suspect there is enough venting of the system so that I don't have a vacuum problem with the drains that would suck out or siphon the trap. I have looked occasionally and always see water in the trap and never any odor. I thought about installing the ~cheater~ but was told that they are 'illegal' to use so thought that if the drain worked as it should I'd not bother install it.
    Thanks again for your responses. If I ever do notice a problem - I'll put in the cheater.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,605
    Location:
    Cave Creek, Arizona
    You can have "all the venting in the system" you want, but that would NOT prevent problems with a sink which does not have a vent but needs one. Venting is a fixture by fixture thing, NOT a whole system cure. THe major problems with lower unvented fixtures is "positive pressure" caused by drainage from upstairs toilets, etc., and that condition is NOT cured by a "cheater vent".
  6. Terry

    Terry Administrator Staff Member

    Messages:
    14,992
    Location:
    Bothell, Washington
    I saw one home that had installed a laundry sink in the basement, using the upstairs kitchen waste line, but did not bring a vent upstairs; tying into the vent above the kitchen. Every time they dumped the kitchen sink upstairs, it would make water burp out of the p-trap downstairs. A downstairs sink without a vent can do goofy things.

    The same home had a back to back shower and soaking tub, installed by a handyman. When the tub was drained, black goo would fill the shower pan. The handyman didn't like installing vents.
    Last edited: Jun 27, 2012
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