BCAB #1569 - Openings in Exit Stair Guards, Sentence 3.4.6.5.(5)

July 18, 2002

BCAB #1569

Re: Openings in Exit Stair Guards, Sentence 3.4.6.5.(5)

Project Description

The project in question is a new apartment building complex. Some exits discharge to grade via open exterior stairs.

Reason for Appeal

Sentence 3.4.6.5.(5) limits the maximum size of an opening in a guard for an exit to one that will allow the passage of a sphere no larger than 100 mm in diameter unless it can be shown that a larger opening will not present a hazard. This appeal deals with the openings in the areas of the guard outlined by the tread, riser and a line drawn through the nosings. The principle reason for limiting the size of openings in guards is to prevent persons, primarily children, from falling through or becoming trapped in a guard.

Appellant’s Position

The appellant contends that the triangular area in question does not present a hazard. If the bottom rail of the guard is about 25 mm above the nosings the opening below is not large enough to allow a small child’s head to pass under the guard. The width of the body laying on the tread positions the head such that it cannot pass below the guard. A six to eight month old infant’s head could pass through the opening but an infant of that age is very unlikely to moving about on a stair on their own. Small children much older than that would have great difficulty squeezing under the guard.

Building Official's Position

The building official maintains that the size of openings in the disputed triangular areas should be limited to the 100 mm diameter sphere. The previous BC Building Code (1992) specifically exempted this space from the limitation on opening size but this exemption does not appear in the current Code. This implies that the limitation applies. Both the AIBC/APEGBC/BOABC Interpretation Committee and staff at the Canadian Codes Centre support the application of the opening size limit to the area in question.

Appeal Board Decision #1569

The Board is satisfied that the intent of Sentence 3.4.6.5.(5) includes the triangular area in question. It is the determination of the Board, that in the absence of definitive evidence to the contrary, the triangular area could present a hazard and should comply with Sentence 3.4.6.5.(5). There may be circumstances where a risk analysis would indicate no hazard but this would have to be determined on an individual basis by the designer or builder and the authority having jurisdiction.

George Humphrey, Chair