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Opinions & Applications for the Fire Code (1997 edition) (revoked November 21, 2007)

9.6.2.12. VERTICAL SERVICE SPACES

9.6.2.12. "(1) Vertical service spaces shall be separated from the remainder of the building by a fire separation having a 45-min fire-resistance rating.

(2) Where openings in the vertical service space, including the top and bottom, are sealed with non combustible materials having the same fire-resistance rating as the existing construction, the vertical service space shall be deemed to be in compliance with Sentence (1)."

Intent:

The intent of this Article is to minimize smoke and fire spread from one floor to other floors through any vertical shafts in the building. Vertical shafts in buildings may be used to enclose elevators or for the passage of building services such as electrical wiring or plumbing and drainage pipes.

Other Resources:

OBC 3.5.3.

Application:

Q1 Can electrical closets be considered part of a vertical service space where floor penetrations of services can not be fire stopped?

A1 Where service penetrations through the floor assemblies are not fire stopped, the closets are considered to be a part of a vertical service space and would have to be protected in accordance with this Article.

Where the service penetrations are fire stopped in accordance with the Building Code, the closets would not have to be treated as part of a vertical service space but would still require a rated fire separation from the corridor. Assuming that the closets only contain panelboards supplying branch circuits for the floor area, it should be sufficient to ensure that the doors are solid wood or metal and if kept locked at all times, self-closing devices are not required.

Q2 Is a vertical service space permitted to be used as part of a fire separation between two suites?

A2 Yes. A vertical service space may form a fire separation between two suites provided that the fire-resistance rating between the two occupied fire compartments is maintained through the cross-section of the vertical service space. It is necessary for the outside membranes of the vertical service space to be constructed in accordance with the requirements set by Retrofit for the fire separation.

Q3 There is a series of electrical closets where it is not possible to fire stop the penetrations through the floor between adjacent closets. Each closet is separated from adjacent suites by a partition with exposed steel studs on the closet side and gypsum board on the suite side. The closets are separated from the corridor by hollow wooden doors. Can these vertically connected electrical closets be treated as being the equivalent of a vertical service space and use Sentence 9.6.2.12.(2) to accept the existing wall construction, even though it is not a proper fire separation?

A3 The intent of Article 9.6.2.12. is to prevent the spread of smoke and fire from an occupied portion of a floor space to the floors above. Sentence (2) ensures a continuous fire resistant membrane exists around the entire vertical service space, thereby preventing the spread of smoke and fire into the shaft. This differs from what is required for new construction under the Building Code. The intent of Article 9.6.2.12. would be met if the vertically connected electrical closets were treated as being the equivalent of a vertical service space and the existing wall construction was accepted under Sentence 9.6.2.12.(2). The existing hollow core wood doors would have to be replaced because Sentence 9.6.2.12.(2) is quite specific in requiring non-combustible materials. The electrical closets could not be used for storage of any type since they would then become storage rooms and subject to different separation requirements.

9.6.2.16. SMOKE CONTROL MEASURES

9.6.2.16. "(1) Buildings where the vertical distance between the floor of the top storey and grade exceeds 18m shall have smoke control measures in accordance with Article 3.2.6.2. of the Building Code.

(2) A building shall be deemed to be in compliance with Sentence (1) where

(a) all dwelling units have access to an exterior balcony,

(b) the length of public corridors does not exceed 30m between exits,

(c) public corridors on each floor area are equipped with smoke detectors connected to the fire alarm system,

(d) public corridors on each floor area are subdivided in accordance with Sentence (3), or

(e) the building is fully sprinklered.

(3) The public corridor subdivision referred to in Clause (2)(d) shall

(a) separate the corridor into a least two compartments by a fire separation,

(b) be located so that no more than one of the required exit stairs is located in any one compartment and the distance of travel from any suite entrance door to an exit or adjacent compartment does not exceed 25m, and

(c) include smoke tight doors equipped with self-closing devices that act as closures in the fire separation."

Intent:

Smoke migration due to stack effect through service penetrations of floors and vertical shafts has been identified as a major cause of injuries and fatalities in high buildings. In order to control the problem, this Article includes a requirement for smoke control measures in accordance with the Building Code. However, recognizing that full implementation of such measures in an existing building is difficult, alternative provisions and exceptions have been provided in Sentence (2).

Other Resources:

OBC 3.2.6.2., NBC Supplement - 1990

Application:

Q1 Do all conditions listed in Sentence (2) have to exist before smoke control requirements can be waived?

A1 No. Any one of the five conditions is considered to be an acceptable alternative measure.

Q2 What is meant by the term "smoke tight" for doors in a cross corridor separation?

A2 A smoke tight door is one that has a smoke seal and is designed and fitted in the same manner as a door in a fire separation but does not need to be rated. When properly installed, the door will provide access to the floor area and will prevent the unimpeded movement of smoke.

Q3 For the public corridor separation referred to in Sentence (3), does it matter in which direction the doors swing?

A3 No, but wherever possible, paired doors should be used that swing in opposite directions to avoid creating a dead end corridor.

9.6.3.1. ACCESS TO EXITS

9.6.3.1. "(1) Each dwelling unit or suite in a floor area shall have a doorway leading to

(a) the outside at or near grade,

(b) an outside passageway where it is possible to go in opposite directions to separate exits, or

(c) a public corridor where it is possible to go in opposite directions to separate exits.

(2) Access to exits through a dead end public corridor shall be deemed to be in compliance with Clause (1)(c) where the distance of travel, measured from any door along the corridor to a point where a choice of two directions of exit travel is available, does not exceed 6m plus the width of the corridor.

(3) Existing dead end public corridors shall be deemed to be in compliance with Sentence (2) where additional fire protection measures are approved that, in the opinion of the Chief Fire Official, will provide protection for life safety similar to the protection provided by compliance with Sentence (2).

(4) Despite Sentence (1), a doorway from a dwelling unit or suite may open onto

(a) an exit stairway,

(b) a public corridor served by a single exit, or

(c) an outside passageway served by a single exit stairway.

if the dwelling unit or suite has access to a second and separate exit."

Intent:

Access to exit includes all facilities within a means of egress from a dwelling unit or suite to an exit on the same floor area. Where a public corridor provides the access to exit there must be at least two directions of exit travel from a point just outside each suite entrance door.

Access to exit through an existing dead end corridor (a corridor providing only one direction of exit travel) is acceptable provided the distance of travel from any suite entrance door along the dead end corridor to a point where at least 2 directions of exit travel are available does not exceed 6m plus the width of the dead end corridor.

The hazard associated with a dead end corridor is that fire and smoke in the corridor could effectively cut off the only means of egress for all rooms in that corridor. Limiting the length of the corridor and thereby the number of suites having access to the corridor will also reduce the possible sources of a hazard and the number of persons who could be subjected to that hazard.

In addition, it may be difficult to locate exits where visibility is reduced due to smoke. Occupants would be forced to feel their way along the corridor wall in their search for an exit. Dead end corridors would substantially increase the time necessary in locating an exit.

Dead end corridors that exceed the maximum length may be approved by the Chief Fire Official if additional fire protection measures are provided. These measures may include enhanced fire detection and automatic fire suppression.

Apart from the limited access through dead end corridors, this Article ensures that there are at least two exit alternatives from each dwelling unit. For this reason, dwelling units that open directly on to an exit facility or public corridor served by a single exit must have access to a second and separate exit.

Other Resources:

NFPA 101; Commentary on O.Reg. 627/92

Application:

Q1 What additional measures may be considered where the length of a dead end corridor exceeds that permitted?

A1 There are a number of options that can be considered where, depending on the existing conditions, one or a combination of alternatives might be used. These alternatives may include sprinklering of the floor area, smoke detection in the corridors, heat detectors in the suites and cross-corridor fire separations. (see also A1 to 9.5.3.1.)

Q2 Is an exit permitted to open onto the first floor, then through the lobby and out of the building?

A2 This is acceptable provided there is at least one other exit that does not lead through the lobby and the building is in conformance with the exiting through lobby requirements contained in Article 3.4.4.2. of the Building Code.