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RWALD Member Posts: 21
I Know this is not heating related but I figured its worth a shot. My question is if my shower or sink drain is less than 5 feet from my main sewer line do i still need to vent it?


  • Intplm.
    Intplm. Member Posts: 1,798
    If there are no other fixtures draining from above in the main sewer then maybe not.

    There are single fixture vents called sudor vents, or sure vents that can be used.

    Your local codes and building department can also help with this question.
  • Jamie Hall
    Jamie Hall Member Posts: 22,924
    Sometimes. This is called wet venting and in certain conditions it is permitted -- and the conditions differ with codes, so you will need to check whatever code is in force in your area.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,236
    Hi, thinking just of the physics involved, I'd vent it, with something like a Studor vent, which is a brand of air admittance valve. If there is no vent, than you're trusting that the trap will never have the water sucked from it by a pull from the main sewer line, and that seems optimistic. When the water is pulled from the trap, you'll know because of that hard-to-ignore sewer gas aroma :#

    Yours, Larry
  • hot_rod
    hot_rod Member Posts: 21,862
    edited April 2022
    another method that was used is called stack venting. All the fixtures on one level were 5’ from a main 3” vertical drain which carried through to the roof. Plenty of air space to vent all the fixtures connected to the “stack”

    It depends on the type of DWV system you have, 
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • rick in Alaska
    rick in Alaska Member Posts: 1,452
    On the places using the UPC, you can do it, but it depends on what else is connected to than line, and how the vent its tied in. In short, you can run the 2" line five feet before you have to have a vent on it. But, it depends on what else is going on.
    RWALD Member Posts: 21
    Thanks guys I'll vent it