BCAB #1713 - Lateral support at the top of foundation walls, Sentence 9.15.4.2.(3)

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