BCAB #1322 - Combustible Water Pipe in Concrete Floor Slab, Sentences 3.1.7.2.(1) & 3.1.7.2.(4)

September 22, 1993

BCAB #1322

Re: Combustible Water Pipe in Concrete Floor Slab, Sentences 3.1.7.2.(1) & 3.1.7.2.(4)

Project Description

The project in question is a four storey noncombustible apartment building. The floor assemblies are reinforced concrete slabs with a 1 hour fire resistance rating. Combustible water pipe inside combustible conduit is embedded in the top half of the 61/2 " thick concrete floor slabs. This pipe runs only within the suites and connects to copper risers via copper manifolds concealed in the fire separations between suites.

Reason for Appeal

Sentence 3.1.7.2.(1) of the 1985 B.C. Building Code requires that "...pipes...that partly...penetrate an assembly required to have a fire resistance rating shall be noncombustible unless the assembly has been tested incorporating such equipment." An exception to this requirement is Sentence 3.1.7.2.(4) which permits combustible conduit to be embedded in a concrete floor slab with a fire resistance rating providing there is at least 50 mm of concrete below the conduit. There is a disagreement as to whether or not these two Sentences permit the proposed water distribution pipe installation described above.

Appellant's Position

The appellant contends that because the concrete floor slabs are more than double the thickness required for the 1 hour fire resistance rating the pipes embedded in the top half of the slab do not "partly or wholly penetrate an assembly required to have a fire resistance rating". The appellant considers the pipes to be embedded in what is essentially a "concrete topping".

Building Official's Position

The building official maintains that although the combustible conduit is permitted by Sentence 3.1.7.2.(4) the combustible water pipe within it still penetrates the fire rated floor slab and Sentence 3.1.7.2.(1) does not permit this unless the slab has been tested incorporating the pipe and conduit.

Appeal Board Decision #1322

The Board considers the full 61/2" concrete floor slab in this building constitutes the fire separation between storeys. It is the determination of the Board that despite the thickness of the slab, Sentence 3.1.7.2.(1) of the Code does not permit the installation of the combustible pipe in combustible conduit within the slab unless such an assembly has passed the CAN4-S101 fire resistance test or unless otherwise accepted by the building official under Section 2.5, "Equivalents."

George R. Humphrey, Chair