- 2075 Bhadra · 4 marks
Essential requirements and types of stair by shape
Short answer
Requirements: accessible, width, riser/tread (2R+T 580-600 mm), pitch 25-40 deg, 3-12 steps, landings, headroom 2.0-2.2 m, strength, handrails, non-slip. Shape types: straight, quarter-turn, dog-legged, open-well, half-turn, three-quarter turn, bifurcated, geometrical, spiral.
What are the essential requirements of good stair? State different types of stair as per shape.
Essential requirements of a good stair
- Location: easily accessible, centrally placed, well lit and ventilated, and near the main entrance; not through rooms.
- Width: residential at least 0.9-1.0 m, public buildings 1.5 m or more (as per NBC and local building bye-laws), so that two persons can pass.
- Easy and safe ascent: riser 150-175 mm (public buildings not more than 150 mm), tread 250-300 mm; about 580-600 mm; all steps in one flight equal.
- Pitch: between 25 and 40 degrees.
- Number of steps per flight: not more than 12 and not less than 3.
- Landings: provided at turns and between flights, with a width not less than the stair width.
- Headroom: at least 2.0-2.2 m clear above every step.
- Strength and fire resistance: strong enough for the live load; fire-resistant material, with a separate fire-escape stair in tall buildings.
- Handrails and balustrades: about 0.9 m high, strong and safe for children.
- Surface: non-slip treads, good lighting and ventilation, durable and pleasing in appearance.
Types of stair as per shape
| Type | Description |
|---|---|
| Straight (single flight) | One continuous flight between two floors, no turn |
| Quarter-turn | Direction changes by 90 degrees at a quarter-space landing |
| Dog-legged | Two flights in opposite directions with a half-space landing and no well between the flights |
| Open-newel / open-well | Two or more flights with a clear well between them |
| Half-turn (two-flight) | Turn of 180 degrees, either dog-legged or open-well |
| Three-quarter turn | Three flights turning through 270 degrees around a well |
| Bifurcated (branching) | One wide flight splits into two narrower flights at a landing |
| Geometrical | Curved (circular or elliptical) flights round an open well, without newel posts; continuous handrail |
| Spiral / circular (helical) | Winder steps radiating round a central post or on a circular plan; saves space |
✓ Answer checked by Claude Opus 5.5 (high effort)
Related questions
- Requirements of a good staircase · Building Technology, chapter 5
- Requirements of good roof; pitched roof types · Building Technology, chapter 4
- Dog-legged stair, 4.5 m by 3.0 m lobby · Building Technology, chapter 5
- Dog-legged stair, 5.0 m by 4.0 m · Building Technology, chapter 5
- Open-well stair, 5.5 m by 3.5 m · Building Technology, chapter 5
- Elements and types of stair · Building Technology, chapter 5 · asked 2×
- Good insulating material requirements and applications · Electric Machine Design, chapter 1 · asked 2×
- Requirements of a good pipe material · Water Supply Engineering, chapter 8 · asked 2×
- Good pipe requirements; expansion joint · Water Supply Engineering, chapter 8 · asked 2×
- Requirements of a good radio receiver; superheterodyne · Communication Systems, chapter 2