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BCAB #1790 - Capillary Break Using an Open Drainage Mat Material

Last updated on June 21, 2017

December 15, 2016

BCAB #1790

Re:  Capillary Break Using an Open Drainage Mat Material, Clause 9.27.2.2.(1)(b)

Project Description

The project is a single family dwelling within the scope of Part 9 of the 2012 BC Building Code. The building requires an exterior cladding assembly consisting of a first plane of protection and a second plane of protection incorporating a capillary break in accordance with Sentence 9.27.2.2.(5).

Reason for Appeal

The local authority considers that the proposed capillary break, which incorporates the drainage mat material requires further documentation to demonstrate that it possesses the necessary characteristics to perform its intended functions when installed, as required by Sentence 1.2.2.1.(1) of Division A.

Appellant's Position

The appellant contends that the proposed drainage mat material meets the specifications of Clause 9.27.2.2.(1)(b). The product has been tested using recognized ASTM test methods by a third party, both on its own and incorporated in a stucco cladding assembly.  In both cases the material met the code's specifications of at least 9.5mm thick, and at least 80% open.

Local Authority’s Position

The local authority maintains that Sentence 1.2.2.1.(1) of Division A provides the option to request a test to determine that the drainage mat material possesses the necessary characteristics to perform its intended use and will maintain its characteristics of a minimum 9.5mm thick and 80% as installed.  Alternatively, the appellant  may have a Registered Professional perform a field review to confirm the material is installed as per the intended use and that Sentence 2.2.2.1.(1) of Division C, which requires that sufficient information be provided to show that the proposed work will conform to the Code, has been complied with. 

​ Appeal Board Decision #1790

It is the determination of the Board that:

  • the drainage mat material possesses the necessary characteristics to meet the prescriptive requirements of Clause 9.27.2.2.(1)(b)
  • Sentence 2.2.2.1.(1) of Division C provides the local authority with the ability to require sufficient information to show that the proposed work will conform to the code, including Sentence 1.2.2.1.(1) of Division A
  • where information is requested in accordance with Sentence 2.2.2.1.(1) of Division C, there is no requirement that this information be provided by a registered professional.

Reason for Decision

Third party testing has been submitted to confirm the drainage mat material conforms to Clause 9.27.2.2.(1)(b).

For matters other than those described in Clause 9.27.2.2.(1)(b), the code enables the local authority to require further information.

Requirements for registered professionals are generally addressed in Subsection 2.2.7. of Division C.

Lyle Kuhnert
Chair, Building Code Appeal Board