November 6, 2017
Re: Permitted Use of Air Admittance Valves
The project is an island counter with a kitchen sink and dishwasher in a dwelling unit. For the purpose of plumbing drainage and venting, it is intended that the dishwasher will discharge into the drain tailpiece of the adjacent sink, upstream of a p-trap. A vent terminating with an air admittance valve (AAV) is proposed to vent the p-trap in lieu of a vent pipe terminating at the outside air.
Applicable Code Requirement
Sentence 184.108.40.206.(1) of Division B of the 2012 British Columbia Plumbing Code
220.127.116.11.(1) An air admittance valve shall only be used to vent
a) fixtures located in island counters,
b) fixtures that may be affected by frost closure of the vent due to local climatic conditions,
c) fixtures in one- and two-family dwellings undergoing renovation, or
d) installations where connection to a vent may not be practical.
Decision being Appealed (Local Authority’s Position)
The local authority has determined that Clause 18.104.22.168.(1)(a) may only be applied if conventional venting is not practical per Clause (d).
The appellant maintains that the wording of Sentence 22.214.171.124.(1) incorporates an ‘or’ clause and that only one of the clauses (Clause 126.96.36.199.(1)(a), (b), (c) or (d)) must be satisfied in order to comply with the Sentence. The use of an AAV is not dependent on the inability to conventionally vent the system.
The appellant has identified and contends that all other requirements of Subsection 2.5.9. have been met.
Appeal Board Decision # 1801
It is the determination of the Board that only one of the four Clauses in Sentence 188.8.131.52.(1) needs to be met in order to comply with the Sentence. Therefore, where a fixture is located in an island counter, the practicality requirement in Clause (d) need not be considered.
Reason for Decision
As Sentence 184.108.40.206.(1) indicates (a), (b), (c) or (d), the Board considers these Clauses to be independent because they are all separated by an ‘or’ (see following excerpt from the preface to the National Building Code of Canada).
Further, Article 220.127.116.11. (Division A) give guidance for non-defined terms, and the term ‘or’ is defined by the Merriam-Webster Dictionary as “used as a function word to indicate an alternative”.
From the National Building Code of Canada preface:
Meaning of the words “and” and “or” between the Clauses and Subclauses of a Sentence
Multiple Clauses and Subclauses are connected by the word “and” or “or” at the end of the second last Clause or Subclause in the series. Although this connecting word appears only once, it is meant to apply to all the preceding Clauses or Subclauses within that series.
For example, in a series of five Clauses—a) to e)—in a Code Sentence, the appearance of the word “and” at the end of Clause d) means that all Clauses in the Sentence are connected to each other with the word “and.” Similarly, in a series of five Clauses—a) to e)—in a Code Sentence, the appearance of the word “or” at the end of Clause d) means that all Clauses in the Sentence are connected to each other with the word “or.”
In all cases, it is important to note that a Clause (and its Subclauses, if any) must always be read in conjunction with its introductory text appearing at the beginning of the Sentence.
Chair, Building Code Appeal Board