9.8.7.2. Continuity of Handrails

 This Article indicates where handrails must be continuous and where they can be interrupted. Continuous handrails provide directional cues for sight-impaired persons and reduce the risk of falls for persons with mobility impairment who rely on handrails for support. The guidance and support provided by handrails is particularly important at the beginning and end of ramps and flights of stairs, and at changes in direction, such as at landings and winders. 

For stairs and ramps serving a single dwelling unit or a house with a secondary suite (including their common spaces), handrails must be continuously graspable throughout the length of ramps and flights of stairs, from the bottom riser to the top riser, but are permitted to start from a newel post or volute installed on the bottom tread (Figure 9.8.-13). For other stairs and ramps, at least one required handrail must be continuous throughout the length of the stair or ramp, including at landings except where interrupted by doorways. 

Quoted from Illustrated User's Guide - NBC2015

9.8.7. Handrails

Handrails are intended to reduce the risk of falling on stairs and ramps. They must be located so that they can be reached by users at any position on the stair or ramp.

9.8.7.1. Required Handrails 

This Article indicates where handrails are required and states some exceptions to these requirements. Handrails on stairs and ramps provide additional support for the physically impaired and guidance for the sight-impaired. They have a different purpose than guards and guardrails, which are primarily intended to prevent people from falling off the side of a stair or ramp.

Quoted from Illustrated User's Guide - NBC2015

9.8.6.3 Dimensions of Landings

This Article establishes minimum dimensions for landings, and addresses the various situations that have an impact on the minimum dimensions, such as doors opening onto landings, and stairs with different widths ending on the same landing. These minimum dimensions are intended to provide enough room to accommodate door swing and to allow safe passage.

A landing should provide sufficient room for a person to stand while opening or closing a door. The general rule is that the landing should be as wide and as long as the width of the stair or ramp that it serves.

Quoted from Illustrated User's Guide - NBC2015

9.8.6.2. Required Landings

This Article indicates where landings are required. In general, landings must be used to provide occupants with a level area at the top and bottom of ramps and flights of stairs, where a doorway opens onto a stair or ramp, where a ramp opens onto a stair, and where a stair opens onto a ramp. They can also be used to make changes in direction or to break a long stair or ramp into shorter runs. Excessively long stairs and ramps are psychologically intimidating and physically tiring, and can be a cause of serious falls.

Where a door at the top of a stair within a dwelling unit swings away from the stair, no landing is required between the doorway and stair. A landing may be omitted at the top of an exterior stair serving a secondary entrance to a single dwelling unit or a house with a secondary suite, provided the stair contains no more than three risers and the principal door to the entrance is a sliding door or swings away from the stair (Figure 9.8.-9).

Quoted from Illustrated User's Guide - NBC2015

Ramps in a barrier-free path of travel

Ramps in a barrier-free path of travel must conform to the requirements in NBC Article 3.8.3.5., as shown in Figure 9.8.-7

Quoted from Illustrated User's Guide - NBC2015

#ramps #barrierfree

9.8.8.6. Design of Guards to Not Facilitate Climbing

This Article requires that guards that protect a level located more than 4.2 m (13 ft. 9 3/8 in.) above the adjacent level, except for those in industrial occupancies, be designed so that no member, attachment or opening located between 140 and 900 mm (5 1/2 and 36 in.) above the level protected by the guard facilitates climbing. Such guards must not be constructed with decorative features that young children could use as a foothold.

Some configurations of members, attachments or openings may be part of a guard design and still comply with NBC Sentence 9.8.8.6.(1). Figures 9.8.-21 to 9.8.-23 present a few examples of designs that are considered to not facilitate climbing.

Quoted from Illustrated User's Guide - NBC2015

#openings #guards #climbing

Dimensions for Rectangular Treads

The limits on the run, together with those on the rise, control the steepness of stairs, which is also a factor in accidents. The minimum run, which is equal to the minimum tread depth, is intended to provide sufficient room to accommodate the length of a foot. Insufficient tread depth causes users to walk sideways to get sufficient foot support, increasing the risk of missteps. The maximum run, on the other hand, is intended to prevent users from having to take more than a single stride between steps, which would decrease the speed of travel. The maximum tread depth is intended to prevent excessive nosing projection. 

The dimensional requirements for steps with rectangular treads in private and public stairs are summarized in Figure 9.8.-2. 

Height over Stairs

These clear heights are intended to provide sufficient headroom clearance to prevent a reasonably tall adult from making accidental head contact with the ceiling or other objects at that height (e.g., light fixtures, sprinklers heads, or piping). The lower minimum clear height for stairs in dwelling units is rationalized on the basis of greater occupant familiarity. 

The clear height requirements for stairs are illustrated in Figure 9.8.-1.

Quoted from Illustrated User's Guide - NBC2015

Hallway

 The minimum unobstructed width of a normal hallway within a dwelling unit is 860 mm (34 in.), but this minimum hallway width is permitted to be reduced to 710 mm (28 in.) when certain requirements are met, as illustrated in Figure 9.5.-2. Hallways narrower than 860 mm (34 in.) must serve only bedrooms or bathrooms at the end of the hallway furthest from the living area, and must have an exit at that end of the hallway or an exit in each bedroom served by the hallway.

Parking Garage Considered as a Separate Building

Sometimes several buildings are built over a common basement used as a parking garage. For example, in certain housing designs, separate low-rise buildings are built over a common basement parking garage (Figure 9.1.-8).

Ordinarily, such a structure would be considered a single building, and the building area would be the area of the basement parking garage. Because this area tends to be fairly large, the entire building would normally fall outside the scope of NBC Part 9. If, however, the basement parking garage is separated from the buildings above it by a concrete or masonry slab having a fire-resistance rating of at least 2 h, these buildings can be considered separate buildings (NBC Article 9.10.4.3). 

In Figure 9.1.-8, buildings A and B would be considered as separate buildings having their own building areas and would probably fall within the scope of NBC Part 9. The parking garage, however, would probably fall outside of the scope of NBC Part 9 because of its large area. 

Quoted from Illustrated User's Guide - NBC2015

#building #parking #basement #sepratebuilding