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BCC Ruling No. 97-35-577

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

AND IN THE MATTER OF Article "the Building Code" (Ontario Regulation 419/89 as amended by Ont. Reg. 183/88, 581/88, 11/89 and 115/89)

AND IN THE MATTER OF an application by Mr. Mike Jones, Vice President, Exal Aluminium Inc., Pickering, Ontario, for the resolution of a dispute with Mr. Leo Grellette, Chief Building Official, Town of Aurora, Ontario, concerning whether the proposed sprinkler and egress facility upgrades from an interior office mezzanine provide sufficiency of compliance with Article of the Ontario Building Code at 95 Dunning Avenue, Aurora, Ontario.


Mr. Mike Jones
Vice President
Exal Aluminium Inc.,
1850 Clements Road
Pickering, Ontario,


Mr. Leo Grellette
Chief Building Official
Town of Aurora


Mr. Roy Philippe (Chair)
Ms. Susan Friedrich
Mr. Lawrence Glazer


Toronto, Ontario


Tuesday, August 12th, 1997


Mr. Mike Jones
Exal Aluminium Inc.
Pickering, Ontario
The Applicant

Mr. Peter Colquhoun
Arencon Inc.
Mississauga, Ontario
Agent for the Applicant

Mr. Leo Grellette
Chief Building Official
Town of Aurora
The Respondent


  1. The Applicant

Mr. Mike Jones, Vice President, Exal Aluminium Inc., is a person who is applying for a building permit under the Building Code Act, 1992 to upgrade the fire safety performance of the aluminium manufacturing plant, especially the two level interior office space at Exal Aluminium Inc., Aurora, Ontario.

  1. Description of Construction

Exal Aluminium manufactures extruded aluminium products at their 95 Dunning Avenue location in Aurora, Ontario. The plant was originally constructed in 1960 and has been added to during several phases, the latest being completed in 1995.

The building is described as a noncombustible, one storey structure, with a total building area of 16,648 m2. There are several mezzanines located in the older areas of the plant that serve as the lunchroom, change rooms and offices. Some of the existing mezzanine structures are constructed of combustible materials.

The building is equipped with a fire alarm system, a standpipe and hose system and a supervised, automatic sprinkler system that serves the entire plant, except for the older office mezzanine area which is separated from the remainder of the building by a masonry wall. The structure is classified as having a Group F, Division 2 major occupancy.

During the last construction phase a one storey addition (the "95 addition") was added to the south end of the existing building. As this project was nearing completion, a two level mezzanine, composed of combustible construction (wood), was added as office space along the west exterior wall of the plant where the '95 addition intersects with the older building. The upper level of this mezzanine is considered to be enclosed and has an area of roughly 112 m2. The sprinkler system in the plant provides some protection for the new mezzanine. The mezzanine was not detailed in the plans submitted and approved for the '95 addition.

The existing construction of the mezzanine is 2 x 4 wood stud walls, 2 x 12 wood joists and 5/8 inch tongue and groove plywood. The plywood floor is covered by vinyl composition tiles. Both the upper and ground floor levels have an acoustic panel suspended ceiling. (The ceiling space on both levels is used as a return air plenum.) The interior walls of the offices are covered by half inch gypsum board, whereas the exterior mezzanine walls that face into the rest of the plant are sheathed with 7/16 inch aspenite and are covered with a pre-finished metal cladding. The mezzanine floor assembly is supported on load bearing wood stud walls that run from the concrete plant floor to the underside of the floor joists.

The sprinkler system in the plant extends at roof level above the mezzanine area. This system, covering the subject area was installed in 1995, and is designed to meet the requirements for Ordinary Hazard Group 2, including the standards for sprinkler spacing. The system complies with NFPA-13 for the occupancy of the building. Below the acoustic tiles and between the ceiling panels and the wood joists of the new office area sprinklers are also installed. This is also served by the 1995 system and is equipped with an 8 inch fire protection water service. The sprinkler system in the mezzanine is consistent with the combustible concealed spaces requirements of NFPA-13-1991, 4- and 4- and it is designed to meet the requirements for a Light Hazard occupancy.

  1. Dispute

The issue at dispute between the Applicant and the Respondent is whether the proposed fire safety upgrades for the mezzanine provide sufficiency of compliance with the requirements of OBC Article Buildings covered by this provision must be of noncombustible construction, and fully sprinklered, while roof assemblies and mezzanines, including supports, must have a fire-resistance rating of at least 1 h. As currently built, the new mezzanine is neither noncombustible nor does it have a 1 h fire-resistance rating.

  1. Provisions of the Building Code

Article Industrial Buildings, Division 2, up to 6 Storeys

(1) A building classified as Group F, Division 2 shall conform to Sentence (2) provided the


(a) is not more than 6 storeys in building height,

(b) if unsprinklered, has a building area not more than the value in Table 3.2.2.V., and

(c) if sprinklered, is not more than twice the area limits of Clause (b).

(2)The building shall be of noncombustible construction, and

(a) floor assemblies shall be fire separations with a fire-resistance rating of not less than 2 h,

(b) mezzanines shall have a fire-resistance rating of not less than 1 hr,

(c) roof assemblies shall have a fire-resistance rating of not less than 1 h, and

(d) all loadbearing walls, columns and arches shall have a fire-resistance rating not less than that required for the supported assembly.

  1. Applicant's Position

The Applicants propose several measures to provide a level of safety that, in their view, would be comparable if the mezzanine was made of noncombustible construction and had a fire-resistance rating of 1 h, i.e., if it complied with Article

Primarily they intend to upgrade the sprinkler system within the mezzanine by replacing the existing heads with quick response sprinklers. This would be done for both the above and below ceiling sprinkler heads. The Applicants also propose to increase the number of sprinkler heads, especially in areas of the mezzanine where coverage is inadequate. They also intend to modify the sprinkler piping to maintain a greater level of pressure and to achieve the higher design standards for an Occupancy Hazard Group 1 classification. The underside of the stairs will also be protected with a layer of 5/8 type X gypsum board. The Applicants argue that these measures would offset the presence of nonrated, combustible material found in the mezzanine, as well as providing protection for the plastic piping and wood framing installed in the plenum.

The access to exits and travel distances have also been considered by the Applicant. It is their belief that the mezzanine is not required to have an additional exit. OBC Sentence requires a mezzanine to have a second exit if the occupant load exceeds 60 persons, or the mezzanine area exceeds (in the case of an F2 occupancy) 200 m2 (2,150 ft2), or the distance of travel is greater than 25 m (82 ft). The subject mezzanine, they claim, has an occupancy of 11 persons, an area of 1,202 ft2, and its greatest travel distance is 77 ft. On these grounds, they argue that it complies fully with OBC Despite their assertion, however, the Applicant is proposing to install an additional steel, open egress stair on the mezzanine's east side, in proximity to the north end.

To improve overall safety for the occupants of the plant, the Applicants will also prepare and implement a fire safety plan for the entire building consistent with Section 2.8 of the OFC.

  1. Chief Building Official's Position

The Respondent submitted that the proposed upgrading measures offered by the Applicant do not provide sufficiency of compliance with Article In particular, they argue that the Code allows sprinklers to be used as a compensating measure to reduce the level fire-resistance rating of roofs, but it does not grant the same relief from the requirements for noncombustible construction, ratings for floors and their supporting structures, and flame spread ratings allowed in concealed spaces used as return air plenums.

The municipality also believes that a second egress is required for the mezzanine because, according to their measurements, the distance of travel from the remotest point on the mezzanine exceeds the limits allowed in Sentence Further, the dead end corridor length of 9 m permitted in the Code is also exceeded in the subject mezzanine.

Finally, the Respondent also notes that the fire safety plan offered by the Applicant is a requirement under the OFC

  1. Commission Ruling

It is the decision of the Building Code Commission that the combustible interior office construction provides sufficiency of compliance with Article of the Building Code provided the sprinkler protection and egress provisions are provided and smoke detection is provided serving the plenum spaces to shut down the mechanical system and activate the fire alarm system.

  1. Reasons:

i) The mezzanine is less than 1% of the building floor area.

ii) The wood framing is protected by drywall or other non combustible finishes.

iii) The sprinkler system is being upgraded to ordinary hazardous group 1 with quick response heads.

iv) Improved egress facilities to serve the mezzanine are being provided, including drywall protection to the underside of the existing stair.

v) The installation of smoke detection serving office plenum space will increase early detection and limit fire spread through fan shut down.

Dated at Toronto this 12th day in the month of August in the year 1997 for application number 1997-39

Roy Philippe, Chair

Susan Friedrich

Lawrence Glazer