July 10, 2012
BCAB #1713
Re: Lateral support at the top of foundation walls, Sentence 9.15.4.2.(3)
Project Description
The project is a Part 9 building which includes a 4 foot high foundation wall with a wood frame pony wall built on top.
Reason for Appeal
The concrete forming method uses sheets of EPS (Expanded Polystyrene) foam as a form face, instead of conventional plywood faced forms. Other forms used consist of manufactured EPS foam blocks.
Appellant's Position
The appellant contends that the foundation walls conform with Table 9.15.4.2.A. as the walls, regardless of the forming method (EPS foam sheets or EPS foam blocks) are 20Mpa concrete, 200mm thick and are not more than 1.2M high. Further, both form materials used conform to the standard referenced in Sentence 9.15.4.1.(1).
Building Official's Position
The building official maintains that Sentence 9.15.4.2.(3) applies to the foundation walls and they must be laterally supported at the top. The walls, as designed, do not conform with Article 9.15.4.3. or with Article 9.20.17.5 as referenced by Sentence 9.15.4.3.(5).
Appeal Board Decision #1713
It is the determination of the Board that the proposed site built EPS forms are not conventional foundation walls on the basis that the form material remains permanently in place. Both the site built and any proprietary foam concrete forms are “insulating concrete form units” and therefore the walls must be laterally supported at the top per sentence 9.15.4.2.(3). The option of design under Part 4 remains available for site built EPS forms that do not conform to Part 9.
George Humphrey, Chair