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BCC Ruling No. 96-44-527

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BUILDING CODE COMMISSION DECISION ON B.C.C. #96-44-527

IN THE MATTER OF Subsection 24(1) of the Building Code Act, 1992.

AND IN THE MATTER OF Articles 3.5.4.3., 6.2.3.2., and Sentence 3.1.5.14.(1) of the Revised Regulation of Ontario 1990, Regulation 61, as amended by O.Regs. 400/91, 158/93, 160/93, 383/94 and 20/95 (the "Building Code").

AND IN THE MATTER OF an application by Ms. Gabrielle McMillan, Manager of Finance and Administration, Canadian Mental Health Association, Windsor-Essex County Branch, Windsor, Ontario, for the resolution of a dispute with Mr. Edward Link, Chief Building Official, City of Windsor, concerning whether the ceiling plenum consisting of a 1 ?" wood roof deck, sprinkler system and smoke detectors provide sufficiency of compliance with Articles 3.5.4.3. 6.2.3.2., and Sentence 3.1.5.14.(1) of the Building Code at the Canadian Mental Health Association, Windsor-Essex County Branch, 1400 Windsor Avenue, Windsor, Ontario.

APPLICANT

Ms. Gabrielle McMillan
Manager of Finance and Administration
Canadian Mental Health Association
Windsor-Essex County Branch
Windsor, Ontario

RESPONDENT

Mr. Edward Link
Chief Building Official
City of Windsor

PANEL

Mr. Roy Philippe, Chair
Mr. Michael Lio
Mr. Michael Steele

PLACE

Toronto, Ontario

DATE OF RULING

September 26th, 1996

APPEARANCES

Mr. Randi Glos
Architect
Randi Glos Architect
Windsor, Ontario
Agent Representing Applicant

RULING

  1. The Applicant

Ms. Gabrielle McMillan, Canadian Mental Health Association is the holder of a permit under the Building Code Act, 1992 to renovate a one storey office (i.e Group D) building at 1400 Windsor Drive, Windsor, Ontario.

  1. Description of Constrution

The subject building is a one storey fully sprinklered Group D occupancy with a building area of approximately 2453 m² (26,406 ft²). It is built with a combination of combustible and noncombustible construction.

The sprinkler system is electrically supervised and the fire alarm system will transmit directly to the local fire department in the event of a fire.

A wood roof deck ceiling return-air plenum which consists of 1346 m² (14,486 ft²) will be sprinklered on both above and below the suspended ceiling in accordance with NFPA 13 standard.

The Applicant proposes to install additional smoke detectors within the return-air plenum that will shut down the air handling system when activated.

  1. Dispute

The dispute between the Applicant and the Respondent concerns sufficiency of compliance with the Building Code. At issue is whether the ceiling plenum consisting of combustible material (1 ?" wood roof deck), sprinkler system and the smoke detectors provide an equivalent level of performance to that intended by the Building Code.

  1. Provision of the Building Code

Article 3.5.4.3. Plenum Requirements

  1. The concealed space between the ceiling and floor or ceiling and roof used as a plenum need not conform to Sentence 3.1.5.14.(1) and Article 6.2.3.2. provided

  1. all materials within the ceiling space have a flame- spread rating of not more than 25 and a smoke developed classification of not more than 50, except for

i. tubing for pneumatic controls,

ii. optical fibre cables and electrical wires and cables that exhibit a flame-spread of not more than 1.5 m (4 ft 11 in), a smoke density of not more than 0.5 at peak optical density and a smoke density not more than 0.15 at average optical density when tested in conformance with the Flame and Smoke Test in the Appendix to CSA C22.2 No. 0.3, "Test Methods for Electrical Wires and Cables" (FT6 Rating),

iii. optical fibre cables and electrical wires and cables that are located in totally enclosed noncombustible raceways (see A- 3.1.4.3.(1)(b)(i) in Appendix A) and

iv. single conductor electrical wires and cables that exhibit a vertical char of not more than 1.5 m (4 ft 11 in) when tested in conformance with the Vertical Flame Test - Cables in Cabletrough in Clause 4.11.4. of CSA C22.2 No. 0.3, "Test Methods for Electrical Wires and Cables" (FT4 Rating), and

  1. the supports for the ceiling membrane are of noncombustible material having a melting point not below 760?C (1400?F).

  1. When the concealed space referred to in Sentence (1) is used as a return-air plenum and incorporates a ceiling membrane that forms part of the required fire-resistance rating of the assembly, every opening through the membrane shall be protected by a fire stop flap which shall

    1. stop the flow of air into the concealed space in the event of a fire,
    2. be supported in a manner that will maintain the integrity of the ceiling membrane for the duration of time required to provide the required fire-resistance rating, and
    3. conform to CAN4-S112.2-M, "Standard Method of Fire Test of Ceiling Firestop Flap Assemblies".

  1. Asbestos paper shall not be exposed in supply and return-air systems.

Sentence 3.1.5.14. Combustible Ducts

  1. Except as permitted by Sentence 3.5.4.3.(1), combustible ducts, including plenums and duct connectors, are permitted to be used in a building required to be of noncombustible construction provided such ducts and duct connectors

    1. are used only in horizontal runs, and
    2. are Class 1 conforming to Article 6.2.3.2.

Article 6.2.3.2. Materials in Air Duct Systems

  1. Except as provided in Sentences (2) to (4) and in Article 3.5.4.3., all ducts, duct connectors, associated fittings and plenums used in air duct systems shall be constructed of steel, aluminum alloy, copper, clay, asbestos-cement or similar noncombustible material.

  1. Ducts, associated fittings and plenums may contain limited amounts of combustible material provided they

    1. conform to the appropriate requirements for Class 1 duct materials in CAN/ULC-S110-M, "Standard Methods of Test for Air Ducts",
    2. conform to Article 3.1.5.14. and Subsection 3.1.9.,
    3. are not used in vertical runs serving more than 2 storeys, and
    4. are not used in air duct systems in which the air temperature may exceed 120?C (248?F).

  1. Duct sealants shall have a flame-spread rating of not more than 25 and a smoke developed classification of not more than 50.
  2. Duct connectors that contain combustible materials and that are used between ducts and air outlet units shall

a. conform to the appropriate requirements for Class 1 air duct materials in CAN/ULC-S110-M, "Standard Methods of Test for Air Ducts",

b. be limited to 4 m (13 ft 1 in) in length,

c. be used only in horizontal runs, and

d. not penetrate required fire separations.

  1. Materials in Sentences (1) to (4) which when used in a location where they may be subjected to excessive moisture shall have no appreciable loss of strength when wet and shall be corrosion-resistant.

5. Applicant's Position

The Applicant submitted that the intent of Article 3.5.4.3. of the Building Code is to prevent the spread of fire and smoke throughout the building as a result of a fire in the ceiling plenum.

The Applicant submitted that the sprinkler system and smoke detectors provide an equivalent level of performance that meets the intent of the Building Code.

The Applicant submitted that in Sentence 3.1.13.6.(2) and Sentence 3.1.13.7.(2) of the Building Code where a building is sprinklered, the requirements for flame spread rating and smoke development classification is considered to be met.

The Applicant submitted that the installation of smoke detectors to shutdown the air handling systems would provide an additional level of safety.

  1. Chief Building Official's Position

he Respondent submitted that the ceiling and the roof deck for the existing building at 1400 Windsor Avenue is being used as a return air plenum for a new HVAC system.

The Respondent submitted that Article 3.5.4.3. specifically states that a concealed space between the ceiling and the roof in a building used as a plenum need not conform to Sentence 3.1.5.14.(1) and Article 6.2.3.2. provided that all materials in the space have a flame spread rating of not more than 25 and a smoke development classification of not more than 50.

The Respondent submitted that there is exposed wood decking in the ceiling space at 1400 Windsor Avenue. This material exceeds both these limits. The Building Code does not allow for trade offs such as sprinklers and/or smoke detectors in ceiling spaces to permit these spaces to be used as plenums where there are materials in the space which exceed these limitations.

The Respondent submitted that Article 2.7.2.2. of the Building Code does not allow for equivalents to be used in lieu of a prescribed Part 3 building system.

The Respondent did not attend the hearing.

  1. Commission Ruling:

It is the decision of the Building Code Commission that the wood roof deck exposed to the plenum space provides sufficiency of compliance with Articles 3.5.4.3. and 6.2.3.2. and Sentence 3.1.5.14.(1) of the Ontario Building Code provided the plenum is sprinklered and equipped with smoke detectors that would shut down the HVAC systems and activate the building's fire alarm system.

  1. Reasons:

i. The Building is classified as Group D occupancy and is less than 30,000 sq. ft in building area, faces onto two streets and is one storey in building height.

ii. The addition of sprinklers in the plenum space significantly reduces the risk of fire spread.

iii. The installation of smoke detectors that upon activation shut down the HVAC systems significantly reduce the possibility of smoke spread in the event of fire.

Dated at Toronto, this 26th day, in the month of Sebtember, in the year 1996, for application number 1996-43.

Roy Philippe

Michael Lio

Michael Steele