Venting system question from Eddie the Novice

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Eddie The Novice, Nov 23, 2012.

  1. Eddie The Novice

    Eddie The Novice In the Trades

    Messages:
    4
    Location:
    Monrovia, CA
    Hey guys,
    I'm glad I finally figured out how to use this message board. I've been visiting this website for a couple of years and learned a lot just by reading all the threads. Here's my situation. I am moving my washing machine and dryer to the garage. They are currently outside in the backyard. I'm in the process of plumbing the garage. I'm running the air vent up to the attic. I was going to shoot the vent pipe straight up out through the roof. Then I realized that you would see the vent from the street. I began to notice that many homes in my neighborhood have all the vents exiting the roof at the back of the house. Could this be a coincidence or do plumbers intentionally do this to avoid all these pipes from sticking out of the roof in the front of the house? If I decide to route the vent through the attic so it can exit through the back of the house, will the additional turns and length of the ABS pipe affect the efficiency of the venting system? Thank you in advance for your input.

    Sincerely,
    Eddie the Novice
  2. Terry

    Terry Administrator Staff Member

    Messages:
    15,117
    Location:
    Bothell, Washington
    If the horizontal is more then 1/3" the vertical, you have to go up one pipe size.
    Most homes have the plumbing toward the back, thus that's where the vents are. How many kitchens have you seen facing the front street?
    Or bathrooms for that matter. If when Plumbing, I'm near the centerline of the home, and I can jog a few feet to be at the back, I sometimes do that.
  3. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    It is a good idea to put the vents in the back. Try to keep the front roof clean. Above the top of your highest fixtures, it is fine to "jog" the vent pipe, just always keep it going UP. Never put a flat horizontal or back sloping pipe, because condensation and rain could fill that up.

    Hate to ask where you are going to DRAIN the WM!~
  4. Eddie The Novice

    Eddie The Novice In the Trades

    Messages:
    4
    Location:
    Monrovia, CA
    So I'm using 2 in ABS black pipe. When the pipe enters the attic, it jogs back nine feet toward the back of the house. After nine feet, it makes a ninety degree turn and exits the roof. The rise is about 2 feet. Does this mean that I should use a larger pipe because my jog was too long?
  5. Eddie The Novice

    Eddie The Novice In the Trades

    Messages:
    4
    Location:
    Monrovia, CA
    Jimbo,
    thanks, I didn't even consider the fact that rain water would come into the vent once it's on the roof. I ran the vent in the attic horizontal because I thought it would look more professional that way. I will go back up and angle it with a downward slope. Thank you so much. This sight is great.
  6. Eddie The Novice

    Eddie The Novice In the Trades

    Messages:
    4
    Location:
    Monrovia, CA
    Jimbo,
    After I finish the venting in the attic, I plan to run a 2 in. ABS pipe all the way to the other end to the house. I will hang the ABS pipe with a gradual incline until it reaches the main big pipe where everything drains out. The pipe looks like it's made of cast iron. It's black. I will splice into that four inch pipe. I think it will work. I'm sort of learning as I go along. I've read a lot of plumbing books for this project.
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