(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 4 of 4

Thread: Vent size?

  1. #1
    DIY Member rick.a's Avatar
    Join Date
    Jan 2007
    Location
    Palmer, Massachusetts
    Posts
    84

    Default Vent size?

    What is the smallest size of vent pipe that can be used to go up from the stack and through the roof? Total load is one toilet, 1 lav sink, 1 shower, 1 kitchen sink. I live in MA if that matters.

    thanks,
    Rick A.

  2. #2
    In the Trades Tom Sawyer's Avatar
    Join Date
    Nov 2010
    Location
    Maine
    Posts
    2,944

    Default

    You can vent the entire bath group with an 1 1/2" pipe but..... you need to go through the roof with 3" minimum

  3. #3
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,659

    Default

    IT is a local code question, but in many cases a toilet needs a 2" minimum vent, and the TOTAL area, NOT diameters, of the vents out the roof has to equal the AREA of the incoming sewer.

  4. #4
    In the Trades Tom Sawyer's Avatar
    Join Date
    Nov 2010
    Location
    Maine
    Posts
    2,944

    Default

    IPC states that the plumbing sytem must have a minimum of one vent through the roof that is 1/2 the size of the building drain which in most cases would be 4" for residential service so... there must be at least one 2" vent through the roof. However in colder climates state and local ammendments will require the vent to be increased to a minimum of 3" where it makes the roof penetration and perhaps 4" in some places. In my state we have to increase to 3" and that 3" must extend 18" below the roof line and at least 12" above.

Similar Threads

  1. Vent size ?
    By Mudball in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 10
    Last Post: 09-15-2009, 01:55 AM
  2. vent size - i know you all love these
    By fidodie in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 4
    Last Post: 12-14-2008, 06:45 AM
  3. Vent Terminal Size
    By seaneys in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 1
    Last Post: 12-28-2007, 05:58 AM
  4. Plumbing Vent Size
    By mlawrence in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 16
    Last Post: 12-04-2007, 08:38 PM
  5. Vent size
    By damorej in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 1
    Last Post: 02-11-2005, 04:33 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •