9.8.4.3.(1)ATTRIBUTION:
Functional Statement:
F30
To minimize the risk of injury to persons as a result of tripping, slipping, falling, contact, drowning or collision.
F10
To facilitate the timely movement of persons to a safe place in an emergency.
Objective:
OS3.1, OS3.7
APPLICATION:
Run and tread depth of rectangular treads in interior
and exterior stairs, for buildings to which Part 9 applies [see Sentence
1.3.3.3.(1) of Division A for application of
Part 9].
This also applies to stairs within dwelling units in buildings to which Part 3 applies [see Sentence
1.3.3.2.(1) of Division A for application of Part 3], as
stated in Sentence
3.3.4.7.(1).
INTENT:
To limit the probability of:
- insufficient tread depth,
- incompatibility between the height of risers and the average user's stride,
- insufficient room to accommodate the length of user's foot, or
- excessively steep stairs.
This is to limit the probability of:
- persons misstepping or tripping, or
- persons misstepping or tripping in an emergency, which could lead to delays in the evacuation or movement of persons to a safe place.
This is to limit the probability of harm to persons.