08-15 Vertical leg/plane

Question: 08-15Code Section: 7Date: 11 May 2008OBC 2006 Reference:

Question submitted: Recently a question has arisen concerning the wording in the code reference (3). The sentence says the distance between the connection of the fixture drain of the fixture and the vent shall not exceed 1000 mm in the vertical plane. Vertical plane is not defined. In the old code the sentence read ‘no vertical leg….’ Vertical leg is defined. Our question is; ‘Should the term vertical plane be replaced with vertical leg or should the term vertical plane be defined?

Interpretation: Vertical leg is still defined and it clearly refers to the change of direction from vertical to horizontal. Vertical plane does not need to be defined as there is no conflict as this code reference is specific. It refers to the VENT connection not being more than 1 meter in the vertical. The dictionary does not define “vertical or horizontal plane”, but If we take each word separately we can define the term. Firstly, the word “plane” refers to a level of existence dealing with flat surfaces, geometrically. The word “vertical” refers to rising perpendicularly from a level surface or upright. The word “horizontal” means parallel to the horizon or level. “Vertical Plane”, means rising vertically and perpendicularly from a horizontal or level surface. A recommendation for an amendment to this section to include the word “nominally” and also amend the definition of “vertical leg” to include the word “nominally”. A further recommendation, that the Code include a sentence that regulates the maximum length of a “vertical leg” to 1000mm.

Approved at AMES 2008 (Code Change Proposal Pending)