Page 113 - Building Regulation Design Guidelines - Architecture Book (Blue Code)

SEcTION: 13 VERTICAL CIRCULATION ELEMENTS SEcTION: 13 VERTICAL CIRCULATION ELEMENTS

13.1.9 For curved staircases, a tread depth of not less than 0.28 meter 13.1.11 For Ladders inclined at 75 to 90-degrees angle require handrail,
at a point 0.30 meter away from the tread’s narrower end, which, shall be extended to 0.9 meter above the platform. Refer
and the smallest radius is not less than twice the stair width. to figure-44 for the minimum dimension for service ladder. Back
(figure -42) guard over 6.0 meters high shall be provided. (figure -44)

W
Riser Wide
Angle R(m) W(m)
T ≥ 0.28m
75° 0.33 1.15
≥ 0.9 m 80° 0.34 1.00
0.36
*W 85° 0.38max 0.90
≤ 0.75 m 90° 0.30min 0.80
0.3m
R ≥ 2*w R W

≤ 2.0 m ≥ 0.9 m
Figure-42 Curved Staircase Dimensions Max. Height of Climb = 5.00 m

3.1.10 For spiral staircases, maximum riser height is 0.18 meter while
depth of tread is not less than 0.28 meter at a point 0.60 meter ≤ 0.75 m
away from the narrower end of the tread. Handrails shall be ≤ 0.75 m
provided on both sides of the stairs. (figure -43)
≥ 0.2 m
R
Handrails Max. Height of Climb = 5.0 m

*W ≤ 2.0 m
0.26 m
0.6 m
≥ 0.28 m
Tread depth
Down
≤ 0.75 m
angle
Figure-43 Spiral Staircase Dimensions Figure-44 Ladder Dimensions

*W = Step Width, *W ≥ (1.10m-1.50m) Depending on Building Type
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