Means of Egress

Means of egress are intended to allow occupants to safely exit a building in an emergency. Egress facilities should be wide enough to allow pedestrian traffic to flow unimpeded and should be designed so that occupants are protected while exiting and can quickly reach an area of safety. Escape routes need to be clearly designated and must not house any activity or item that could hamper evacuation or create a fire hazard.

A means of egress has two distinct components: 

(1) an access to an exit, and 

(2) an exit. 

The access to an exit originates at any occupied location in a floor area and terminates at the exit door through which occupants leave the floor area. The access to an exit is the total path of travel from the occupied location to the exit door, including any intervening rooms or spaces.

The exit begins at the door through which occupants leave the floor area and ends at an exit door that provides access to a separate building, an open public thoroughfare, or an exterior open space protected from fire exposure from the building and having access to an open public thoroughfare. The exit may include enclosed stairways, ramps and passageways. For example, in a multi-level building, the exit may include the door into an exit stairway, the exit stairway, the door out of the stairway, and the exit door to a place of safety outside the building (or in another building). In a simple single-storey building, the exit may consist of only the exterior door, without any other intervening exit facilities. A stair within a dwelling unit is not considered to be part of an exit, but as part of an access to an exit.

Quoted from Illustrated Users' Guide - NBC2015

#building #meansofegress #exit #accesstoexit

9.8.9.2. Exterior Concrete Stairs

 

This Article establishes the support required for exterior concrete stairs. Larger concrete stairs need to have adequate structural support to reduce the risk of uneven movement or settlement caused by changes in soil moisture content or frost. Because of their weight, misalignment or settlement is more difficult to correct for these stairs than for smaller concrete stairs or wooden stairs.

Exterior concrete stairs with more than two risers and two treads are required to be supported on a foundation of unit masonry or concrete walls or piers not less than 150 mm (6 in.) in cross-section, or cantilevered from the main foundation wall, as shown in Figure 9.8.-25. 

The depth below ground level for foundations for exterior concrete stairs must conform to the requirements in NBC Section 9.12. Because pier-type foundations can heave if the soil freezes to the sides of the piers, excavations for piers should be backfilled with drained granular material to reduce this risk (although this is not a requirement).

Quoted from Illustrated User's Guide - NBC2015

#concrete #structural #stair

9.8.8.5. Openings in Guards

 9.8.8.5. Openings in Guards

In general, openings in guards must prevent the passage of a spherical object having a diameter of 100 mm (4 in.) in order to prevent small children from crawling through them.

In industrial occupancies, larger openings are allowed in guards, except where they serve storage garages, because small children are not likely to be present in such occupancies. The guards in such occupancies are permitted to consist of a top railing and one or more horizontal intermediate rails spaced such that the size of the openings through the guard prevents the passage of a spherical object having a diameter of 535 mm (21 in.). This limit on the size of the openings is intended to reduce the risk of an adult falling through the guard. 

In other occupancies, the size range of openings in non-required guards is limited to prevent children from getting their head stuck in the openings.

Quoted from Illustrated User's Guide - NBC2015

#guards #openings

9.8.8.3. Height of Guards

The purpose of a minimum guard height is to ensure that guards are high enough to help prevent accidental falls over the guard. The height of a guard should be close to the waist height of an average person so that jostling or pushing under crowded conditions will not result in accidental falls over the guard.

The lower minimum height for guards serving dwelling units and houses with a secondary suite (including their common spaces), with the exception of exterior guards protecting walking surfaces above a certain height, is rationalized on the basis of occupant familiarity.

In other occupancies, guards protecting level surfaces, such as balconies and landings, are required to be higher than those serving stairs other than required exit stairs. However, the specified minimum height for guards serving stairs, which is measured vertically from the top of the handrail to a line drawn through the tread nosings, corresponds to an effective height in relation to a stair user that is comparable to the specified minimum height for guards serving level surfaces.

Quoted from Illustrated User's Guide - NBC2015
#guards #height

Friendly Reminder - You will never be regretful if you ASK BING before:

 Friendly Reminder - You will never be regretful if you ASK BING before:

1. purchasing a property for your business

2. installing a sprinkler system in a building

Recently, I have two clients:

One purchased one unit of a semi-detached house. He planned to use the unit as an office. He spent thousands of dollars for hiring professionals to design the office for him, besides more than $500k cost of the unit itself. After submitting the plans to the City, the City asked him to upgrade the exsiting1h combustible fire separation between the two units to 2h firewall. It is impossible to build an noncombustible firewall with parapets, unless he demolishes the whole house.

Another is building a new 4 units two storey rowhouse with secondary suites. The designer indicated on the floor plans that sprinkler system will be installed in the building throughout. The contractor was wondering if it is sufficient if the sprinkler system is installed in the basement only. I asked the designer why he wanted to install the sprinkler system in this building. The answer was that all the apartment buildings shall be sprinklered. I was speechless.

9.8.8.1. Required Guards

This Article indicates where guards are required and addresses a number of specific situations related to the protection of doors, windows and glazing. Guards are intended to prevent people from falling from one level to an adjacent level. Generally, guards are required for the open sides of stairs, ramps, landings, balconies, porches, decks, mezzanines, galleries and raised walkways where there is a difference in elevation of more than 600 mm (24 in.) between the walking surface and the adjacent surface or where the adjacent surface within 1.2 m (4 ft.) of the walking surface has a slope of more than 1:2 (Figure 9.8.-15).

Quoted from Illustrated User's Guide - NBC2015

9.8.7.3. Termination of Handrails

This Article indicates that handrails need to terminate in a manner that will not obstruct pedestrian travel or create a hazard. This requirement is intended to reduce the risk of injury to users, particularly those with sight impairment.

Handrails for stairs and ramps serving a single dwelling unit or a house with a secondary suite (including their common spaces) are not required to extend beyond the top and bottom of the stair or ramp. For all other stairs and ramps, at least one handrail is required to extend horizontally not less than 300 mm (12 in.) beyond the top and bottom of each flight or ramp (Figure 9.8.-14). This horizontal extension, which allows the handrail to be grasped while the user is on the landing where there is less risk of falling, is for the benefit of persons with a physical disability or who rely on a cane or crutches for mobility

Quoted from Illustrated User's Guide - NBC2015