Return to the Plumbing Forum | Post a Follow-Up

 o
Horizontal Vents 6 inches above tallest fixture

Posted by spafrica2003 (My Page) on
Wed, Apr 28, 10 at 13:25

I have been told that "code prohibits any horizontal vents until the vent reaches an elevation 6" higher than the tallest fixture served by that vent."

If I want to run a 2" vent off of the 4" stack/vent, do I have to enter 6" above the highest fixture itself or 6" above the highest point on the stack where a drain line enters the stack?


Follow-Up Postings:

 o
RE: Horizontal Vents 6 inches above tallest fixture

6" above the highest fixture itself

It is to make sure the vent stays dry and does not have waste in the line.


 o
RE: Horizontal Vents 6 inches above tallest fixture

A vent line may not run horizontal until it reaches an elevation at least 6" above the highest fixture served by that vent.

The same rule applies to a stack. You may not attach a vent line to a stack until you reach an elevation at least 6" above the flood level rim of the highest fixture served by that stack.

By example, if you are venting a bathroom on the first floor and you need an auxiliary vent, the horizontal offset of that auxiliary vent would need to be at least 6" higher than the lavatory bowl rim in that bathroom. If you want t6o attach that vent to the stack serving both the first and second floor you cannot attach the auxiliary vent to the stack until it reaches a point on the second floor which is 6" higher than the flood level rim of the highest fixture served by that stack on the second floor.

Also, Under the UPC vents are sized by the dfu's load of the fixtures served by that vent, but if there is a horizontal offset longer than 3" the entire length of the vent must be increased one nominal trade size.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Plumbing Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here