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BCC Ruling No. 98-27-632

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

AND IN THE MATTER OF Article of Regulation 61, as amended by O. Reg. 400/91, 158/93, 160/93, 383/94, 20/95 and 395/96 (the "Ontario Building Code").

AND IN THE MATTER OF an application by Mr. Bob Whitcher, Manager, Manufacturing Engineering, Cambridge, Ontario for the resolution of a dispute with Mr. Larry Simonato, Chief Building Official, City of Cambridge, Ontario to determine whether the installed plywood platforms in eight assembly lines should be considered as finished flooring with concealed spaces underneath and therefore subject to Article of the Ontario Building Code at the Toyota Motor Manufacturing Plant, 1055 Fountain Street North, Cambridge, Ontario.


Mr. Bob Whitcher, Manager, Manufacturing Engineering
Toyota Motor Manufacturing Canada Inc.
Cambridge, Ontario


Mr. Larry Simonato
Chief Building Official
City of Cambridge


Mr. Michael Lio (Chair)
Mr. Michael Steele
Mr. Kenneth Peaker


Toronto, Ontario


June 18, 1998


June 18, 1998


Mr. Leszek Muniak, Principal, Larden Muniak Consulting Inc.
Toronto, Ontario
Agent for the Applicant

Mr. Dave Carroll, Supervisor of Building Inspectors
City of Cambridge, Ontario
For the Respondent


  1. The Applicant

Mr. Bob Whitcher, Manager, Manufacturing Engineering, holds a building permit under the Building Code Act, 1992 for the construction of an addition to an automobile manufacturing plant at 1055 Fountain Street North, Cambridge, Ontario.

  1. Description of Construction

The Applicant recently constructed a one storey addition to a manufacturing facility that assembles automobiles. With the addition the plant has a building area of 268,000 m2. The building is constructed of noncombustible construction. It is fully sprinklered and is also equipped with a fire alarm system and a standpipe and hose system. The structure is classified as having a Group F - Division 3 industrial major occupancy. There are also subsidiary office spaces in the plant.

As part of the recent construction, the Applicant installed a series of plywood platforms at eight assembly lines that serve as adjustable work stations. The platforms were made to be adjustable so that they can be positioned to safe and desirable heights as plant employees perform their tasks. Five assembly lines have overhead conveyors that has automobiles suspended above as work is performed underneath. Three other lines are slat conveyors in which the automobiles move through the assembly process on a moving floor conveyor.

On four of the overhead assembly lines, a work pit centred under the conveyor runs the length of the assembly line. Some of the subject platforms are located in these pits, which allow for the necessary clearance of the adjustable work stations. Since the conveyors are purchased as prefabricated units, the pits and moveable platforms are useful so that the conveyors can be made more adaptable.

The area where the automobiles are assembled within the plant is open and comprises approximately 41,600 m2.

  1. Dispute

The issue at dispute between the Applicant and Respondent concerns whether the as constructed plywood platforms should be considered as finished flooring with concealed spaces underneath and therefore subject to Article of the Ontario Building Code. In a building required to be of noncombustible construction, the recently constructed platforms are wood, not steel. Sentence (2) of Article of the OB. allows a raised combustible floor in a noncombustible building as long as the concealed spaces are fire stopped. Most of the platforms exceed the height of 300 mm permitted in Article (even exceeding 375 mm allowed in the 1997 OBC.) and some are not adequately fire stopped. If the platforms are considered to have concealed spaces beneath, they would be required to be fire stopped so that the maximum area of concealed space is limited to 10 m2 or less according to Article The concealed spaces would also be required to be sprinklered as per Article

  1. Provisions of the Ontario Building Code

Sentence Flooring Elements

(2) Wood members more than 50 mm (2 in) but not more than 300 mm (11 3/4) high applied directly to or set into a noncombustible floor slab are permitted for the support of finished flooring in a building required to be of noncombustible construction provided the concealed spaces are fire stopped in conformance with Sentence

Sentence Stopping Between Nailing and Supporting Elements

(2) In a building required to be of noncombustible construction, fire stops conforming to Article shall be provided in the concealed spaces created by the wood members permitted in Sentence so that the maximum area of a concealed space is not more than 10 m2 (108 ft 2).

Sentence Sprinkler Systems

(1) Except as provided in Sentences (2) and (3), where a sprinkler system is required, it shall be designed, constructed, installed and tested in conformance with NFPA 13, "Installation of Sprinkler System".

  1. Applicant's Position

The Applicant submitted that the plywood platforms should not be considered as having concealed spaces and therefore not subject to Article

On a general level, the Applicant argued that the plywood platforms, as opposed to steel, provide more cushioning and flexibility thereby offering more comfort to assembly line workers. As well, the subject platforms are easier to adjust than similar ones made of steel, thus making them more ergonomically friendly because they can easily accommodate the height differences of the various line employees. The Applicant also indicated that the total floor space occupied by the plywood platforms is 2,865 m2. They noted that this represents only 6.9% of the 41,600 m2 assembly floor area.

While recognizing that the potential exists for fire to propagate in the spaces underneath the platforms, they insisted that risk to occupants is limited. The platforms are not part of ameans of egress. Workers can easily get off either side of the platforms onto the concrete floor before the smoke and heat from a potential fire under a platform could cause problems. Since the assembly area is a large, open space evacuation in such a fire could occur in reasonable time.

The Applicant also argued that fire stopping or sprinklering under the platforms is impractical because they are constantly being adjusted up or down depending on the needs of the users.

The Applicant also addressed the specifics of the different types of platforms. The first type, which covers an area of 277 m2, are described as 1,220 mm by 2,440 mm (4 ft by 8 ft) plywood boxes that are laid side by side to create a linear platform. The boxes are 406 mm high, exceeding both the 1990 and 1997 OBC standards. Handhold slots for moving and relocation are provided at the perimeter of each box. When positioned side by side, the handhold slots line up from one box to the next. The Applicant argues that these box-type platforms should be allowed because they are similar to wood flooring allowed under Article with the exception that they are slightly higher which does not appreciably increase the associated hazards. They also note that there is no potential fire sources such as motors, cabling, etc. contained in these platforms.

The second type of platform is also a box type and it covers 447 m2. These boxes are less than 375 mm in height, however, some have a steel framed, prefabricated motor driven conveyor belt beneath. The electric motors below some platforms are the potential ignition points, nevertheless, these have been equipped with a pinch point protection system that provides for metal flaps that cover the space between the edge of the conveyor belt and the box they sit in. These boxes have hinged access hatches to provide quick fire fighting access. The Applicant is recommending that the handhold holes be fire stopped in these platforms.

The last type, at 2,141 m2, occupies nearly 75 % of the platform area. Located in the concrete pits found at the overhead assembly lines, these platforms are 406 mm high, and contain a similar conveyor mechanism (as described above) underneath. This type of platform is not fire stopped under the walking surface. As the Applicant argued, this platform type does meet the intent of Article since it does provide for some inhibiting of the spread of fire in a concealed space because the pit areas themselves are limited in length. As well, it allows occupants an easy opportunity to dismount onto a concrete floor in an open space which, the Applicant stated, provides an immediate and safe access to a means of egress.

Lastly, the Applicant contended that the plywood platforms installed in the manufacturing facility should be viewed more as an adjustable tool and not as a fixed flooring system and should therefore not be required to fire stop and sprinkler below the plywood platforms.

  1. Chief Building Official's Position

The Respondent submitted that the installed combustible platforms do not meet the requirements of the OBC, specifically Sentences, and

The Respondents argued that there were three aspects of the platforms that were not complying with the Building Code. The first issue is that some of the platforms are too high. Applying the 1990 OBC standards, they noted that the maximum height permitted in Sentence was 300 mm (11 3/4 in). Two of the three platform types exceed this height.

The second issue they raised was that was that none of the platforms were fire stopped in accordance with Sentence The Respondents also added that the maximum area of any single concealed space be limited to 10 m2 (108 ft 2).

The requirement for sprinklering the concealed spaces found in Sentence was the third issue brought forward by the Respondent. In their view, the platforms should be built to conform with NFPA 13 standards for sprinklering a concealed spaces found in combustible construction. They noted that none of the platforms are currently sprinklered.

  1. Commission Ruling

It is the decision of the Building Code Commission that the combustible platforms do not provide sufficiency of compliance with the requirements of the Building Code.

  1. Reasons

i)It is the opinion of the Building Code Commission that the platforms are not considered fixtures and are part of the building.

Dated at Toronto this 18th day in the month of June in the year 1998 for application number 1998-26.

Mr. Michael Lio, Chair

Mr. Michael Steele

Mr. Kenneth Peaker