Basement Bathroom Project

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by red22769, Feb 1, 2010.

  1. red22769

    red22769 New Member

    Messages:
    13
    Location:
    USA
    After realizing that to be sure my plumbing is done properly in the bathroom I am adding in my basement,
    I had a highly recommended plumber come over and look over my proposed layout I drew up, and give me a quote and describe to me how he would run the vent pipe to ensure proper venting and passing inspection, etc...

    The sketch below is how he said he would run the drain and vent pipes, and assured me inspections would pass, he does this all the time....I need to run this by the Pro's here because something just doesn't seem right with his design.

    To give some background info, the black soil stack in the sketch drains the 1/2 bath on the 1st level, the laundry room, and a slop sink in the garage ( Pictures of existing stack also included )

    In the sketch, the existing stack is indicated with the solid black line.
    The green dashed lines indicate the new underground pipe he will install after opening up the concrete floor.
    The red lines indicate how each fixture is vented. ( can you vent to an existing soil stack? )
    The blue line simply shows the above ground sink drain to the wall.

    I am in the HVAC industry, and I am not up to snuff on what the local plumbing codes are here in Michigan, but something just seems off with this layout...can i get some feedback to put my mind at ease, or should I look for another plumber?

    Thanks in advance for your help!!

    Attached Files:

  2. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    The new vents must tie into the existing vent sack 6" above the highest fixture.

    John
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,242
    Location:
    Cave Creek, Arizona
    dwv

    The drainage portion looks right, as long as it is actually installed that way. BUT, you cannot connect the vent back to the vertical line because that is a drain NOT a vent. The vent has to be tied into the system above the highest fixtures on the upper floors. Doing it his way creates a "secondary drain" for the upper bathrooms.
  4. red22769

    red22769 New Member

    Messages:
    13
    Location:
    USA
    Thanks hj & john for your feedback!

    Based on what I have read in these forums for the past few weeks, I didn't feel too comfortable with this guys plan.

    I called him to ask a few questions about the vent plan, and how he would connect to the existing line up stairs, and he said he wouldn't need to do that.
    He was planning to use AAV's instead of tieing the vent into the vertical stack after looking at the floor plan of my house a bit closer.
    He said AAV's are approved in MI code, and he uses them frequently, and could offer a reduced price now since there will be less material and time involved.

    Would these AAV's work where he is describing them to me?
    From our conversation, he wants to put one about 48" up inside the shower wall, and another 48" up in the wall where the sink drain will connect.
    There will not be a connection to the vertical soil stack as indicated in the 1st attachment
    ( I modified the sketch based on the description the plumber gave me of his plan )

    I've never seen one of these AAV's before and haven't a clue on what it is, or it's function....common sence tells me they are used for venting, but do they work? Is this common practice?

    I'm pretty sure I need to find someone else to come look at this project!!!!
    What do you all think?

    Attached Files:

  5. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    Personally, if I hired a professional plumber, and he wanted to use AAVs and it wasn't as a last resort, I would find another plumber.

    AAVs work in some situations where you have no other choice, but it shouldn't be your first plan.

    Does your house have an attic?

    The new plumber you hire should run the vent up into the attic and either tie into the exists vent stack or put a new one through the roof, it's really not that difficult.
  6. red22769

    red22769 New Member

    Messages:
    13
    Location:
    USA
    My home is a 2 story with a vaulted ceiling in the master bedroom on the 2nd level directly above where this bathroom would be located in the basement, so no attic access...

    I can however open up the wall in a closet in the laundry room on the 1st floor adjacent to where the bathroom would be. By doing that I can go up in that wall into the attic above the garage. ( In the sketch, the wall the fixtures will be on is the foundation wall for the garage )

    I am planning to put a new roof on in the spring, so can I run it up into this attic space, and leave it just short of the roof until I do the tear off, and then extend it though later? See revised sketch and advise...
    Doing this will incur more drywall work for me, but at least I will know the plumbing and venting is done properly.

    Does the toilet need it's own vent pipe too? or just the shower and sink?

    Attached Files:

  7. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    If the vent for the shower is 2" it will also serve the toilet.

    John
  8. red22769

    red22769 New Member

    Messages:
    13
    Location:
    USA
    BUMP...

    Is leaving the vent pipe open in the garage attic ok until I get the roof done this spring?

    Would like to move forward with the project, but would sleep better with comfirmation from the experts!

    thanks to all who have entered feedback so far!
  9. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    If the plumbing is going to be connected to an already properly vented drain system, I would be fine with piping it up to the attic and putting an AAV on the end of it temporarily. The reason I say this is because sometimes attics aren't sealed from our living spaces nearly as well as they should be, and I wouldn't want to risk gases getting into the home.

    Priority one should be to punch it through the roof when the roofer gets there.

    Keep in mind you have a lot of flexibility with vent lines and they don't need to go directly vertical of the fixture(s) you are venting.
  10. red22769

    red22769 New Member

    Messages:
    13
    Location:
    USA
    Great to know...thanks for the info dlarrivee!

    the construction will be getting underway tonight!
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