H-5 Task 2

Question 1

what are the three categories of stairs in the BC Building Code?

Answer 1

Service stairs, Private stairs, Public stair

Question 2

what are service stairs used for?

Answer 2

access service rooms or spaces
(stairs to an attic or utility room)

these stairs cannot access any living space

Question 3

what are private stairs used for?

Answer 3

interior stairs within a dwelling unit, or exterior stairs serving a single dwelling unit

Question 4

private or public:
stairs in a multi-family housing development, stairs within that unit serving that single family are?

Stairs shared by several units are?

Answer 4

Private for stair within the unit, public for stairs shared by several units

Question 5

Public or Private or service:

which is subject to constraints in part 3 of the BC Building Code Book?

Answer 5

Public stairs, (schools, parkades, and other public buildings)

Question 6

what is the main concern of the BC Building Code when designing and building stairs?

Answer 6

Safety
example, high riser and the run is short, stairs will be quite steep. Conversely, if the rise is too low and the run is too long, the stairs will be very flat.

both situations are dangerous and you don’t want anyone tripping

Question 7

for private stairs, whats the minimum and maximum rise?

what is the most comfortable rise?

Answer 7

125mm to 200mm

180mm (7”) is most comfortable

Question 8

within a single flight, all rises and run must be identical. what is the maximum difference in the rise or run of any two steps in a stairway?

whats the maximum difference in the rise or run between adjacent steps in a stairway?

Answer 8

10mm in the rise or run of any two steps in a stairway

5mm in the rise or run between adjacent steps in a stairway

Question 9

whats the minimum and maximum run for private stairs?

Answer 9

255mm

355mm

Question 10

thickness for lumber or plywood treads for stairs must be at least?

if open risers are used and the distance between stringers exceeds 750mm, whats the minimum thickness?

Answer 10

25mm

38mm

Question 11

what does “tread depth” refer to?

Answer 11

the width of the tread, not the length of the tread.

Question 12

what is the angle of stairs?

degrees

Answer 12

preferred is between 30 and 35 degrees, a 7 in 10 stair has a slope of 35 degrees

Question 13

what is the minimum headroom height for a dwelling unit? (one building, one fam)

Answer 13

1950mm for within dwelling units, 2050mm for all other stairs

Question 14

what is the minimum effective depth for stringers? and what is the minimum overall width of the stringer?

Answer 14

Effective depth of at least 90mm, and overall depth of at least 235mm

Question 15

what is the minimum thickness of a stringer for supported and unsupported along their length?

Answer 15

25mm for supported, 38mm for unsupported

Question 16

what is the maximum spacing of stringers? and what is it the spacing increased to if a riser board supports the leading edge of the tread?

what is the spacing for serving other than single-family unit?

Answer 16

900mm o.c., 1200mm o.c. if riser board supports tread

600mm o.c. whether the riser supports the tread or not

this is minimum, good practice to include a third stringer

Question 17

when are handrails required?

where do the handrails run?

handrail must be provided on at least one side of stairways within dwelling units less than?

Answer 17

when their are more than two risers within a dwelling unit

run continuously along the length of the stairway, including the landings, except where interrupted by doorways, newels or changes in direction

1100mm wide

Question 18

what is the minimum and maximum height of handrails?

what is the clearance from the wall for handrails?

Answer 18

between 865mm to 1070mm in height, measured vertically from the nosing line

50mm

Question 19

how wide are handrails?

Answer 19

handrails must be graspable, without stretching their hand

Question 20

what is the minimum width of a stairway?

single dwelling unit

Answer 20

860mm width between wall faces

Question 21

what takes precedence over proportioning formulas?

Answer 21

BC Building Code minimum 255mm