Staircase Location Plan & Geometry
Sheet 1 of 5
Single-flight dog-leg stair · GF to FF (+3000mm) · 12 risers × 175mm · 11 treads × 250mm · Waist slab 150mm
175
Riser mm
250
Tread mm
12
No. Risers
11
No. Treads
150
Waist mm
3000
Floor–Floor
1200
Width mm
2750
Horiz. span
STAIRCASE PLAN — GROUND FLOOR LEVEL
SCHEMATIC LOCATION IN BUILDING PLAN · 1200mm CLEAR WIDTH · NOT TO SCALETread lines (250mm)
Landing slab
Stringer/support
Columns
DESIGN PARAMETERS
IS 456 · WAIST SLAB METHOD| Parameter | Value | Check |
|---|---|---|
| Riser (R) | 175mm | 150≤R≤200 ✓ |
| Tread (T) | 250mm | 200≤T≤300 ✓ |
| R + 2T | 175+500=675 | 600–660mm ✓ |
| No. Risers | 12 nos. | — |
| No. Treads | 11 nos. | — |
| Floor–Floor | 3000mm | 12×250=3000 ✓ |
| Horiz. span | 2750mm | 11×250mm |
| Waist slab | 150mm | Span/20=138 ✓ |
| Clear width | 1200mm | ≥1000 ✓ |
| Eff. span Le | ~3000mm | Incl. landing |
| Total load w | ~12.4 kN/m² | DL+LL+step |
| Mu (midspan) | ~13.95 kNm/m | wLe²/8 |
| Ast req. | ~330 mm²/m | T10@150=524 ✓ |
| Ast prov. | T10@150 = 524mm²/m | OK ✓ |
| Dist. steel | T8@200 = 251mm²/m | 0.12% ✓ |
| Cover | 20mm | Exposed top |
| d effective | 125mm | 150−20−5 |
Loading calculation (per IS 456):
DL waist: 0.15×25/cosθ = 4.56 kN/m²
DL steps: R/2×25 = 2.19 kN/m²
Finishes: 1.0 kN/m²
LL: 3.0 kN/m²
Total factored: ~12.4 kN/m²
DL waist: 0.15×25/cosθ = 4.56 kN/m²
DL steps: R/2×25 = 2.19 kN/m²
Finishes: 1.0 kN/m²
LL: 3.0 kN/m²
Total factored: ~12.4 kN/m²
Longitudinal Section — Stair Flight
Sheet 2 of 5
Section through stair flight showing waist slab · 12 risers 175mm · 11 treads 250mm · main + distribution bars · landing details
SECTION A–A — LONGITUDINAL THROUGH FLIGHT (GF +0.00 TO FF +3.00m)
WAIST SLAB 150mm · T10@150 MAIN BARS · T8@200 DIST. BARS · T10@150 TOP AT SUPPORTS · SCALE NTSWaist slab + steps M20
T10@150 Main bars (bottom)
T10@150 Top bars @ supports
T8@200 Distribution bars
Landing slab 150mm
Cross-Sections & Step Detail
Sheet 3 of 5
Section B–B at mid-flight · Individual step detail · Bar arrangement · Cover · Effective depth · Kicker detail
SECTION B–B — ACROSS WIDTH
AT MID-FLIGHT · 1200mm WIDTHINDIVIDUAL STEP DETAIL
TREAD + RISER + WAIST SLAB · ENLARGEDWAIST SLAB — SECTION & REBAR
PERPENDICULAR TO SLOPE · BAR LAYERSLanding Slab & Support Details
Sheet 4 of 5
GF landing 150mm slab · FF landing 150mm slab · Support beam/wall connections · Continuity reinforcement
LANDING SLAB REINFORCEMENT — GF & FF
150mm THICK · T10@150 BOTH WAYS · SUPPORT CONDITIONSCONTINUITY REINFORCEMENT DETAIL
FLIGHT–LANDING JUNCTIONSTRINGER SUPPORT CONDITIONS
SIDE WALLS · EDGE SUPPORT| Item | Specification |
|---|---|
| Stringer wall | 230mm brick / RCC wall both sides |
| Bearing length | ≥150mm on support beam |
| GF support | PB 300×450mm or ground beam |
| FF support | GB 230×450mm beam at landing |
| Lateral support | Columns A-1 & A-2 either end |
| Main bar anchorage | Ld = 400mm + 90° hook |
| Top bar extent | L/4 from support face |
| Landing continuity | Continuous with stair bars |
| Handrail wall | 150mm stub wall on waist slab |
Bar Bending Schedule & Engineering Notes
Sheet 5 of 5 · Complete BBS
Complete bar schedule for flight + GF landing + FF landing · steel quantities · IS 456 compliance
COMPLETE BBS — STAIRCASE (FLIGHT + LANDINGS)
ALL BARS · QUANTITIES · WEIGHT| Mark | Item | Bar | Position | Shape | Cut Len (mm) | No. Bars | Total m | Wt (kg) |
|---|---|---|---|---|---|---|---|---|
| STAIR FLIGHT — 150mm Waist Slab (incl. 1200mm wide) | ||||||||
| SF-M1 | Flight main bars | T10 | Bottom parallel slope | Str.+2-hook | 3850 | 9 | 34.7m | 21.4 |
| SF-D1 | Flight dist. bars | T8 | Perp. to slope (bottom) | Straight | 1250 | 20 | 25.0m | 9.9 |
| SF-T1 | Top bars @ GF end | T10 | Top, 800mm from GF spt. | Str.+hook | 980 | 9 | 8.8m | 5.4 |
| SF-T2 | Top bars @ FF end | T10 | Top, 800mm from FF spt. | Str.+hook | 980 | 9 | 8.8m | 5.4 |
| SF-A1 | Anti-crack bars | T8 | Top perpendicular | Straight | 1250 | 10 | 12.5m | 4.9 |
| GF LANDING SLAB — 150mm (1200 × 600mm) | ||||||||
| GL-M1 | GF landing main | T10 | Bottom span direction | Straight | 700 | 9 | 6.3m | 3.9 |
| GL-D1 | GF landing dist. | T8 | Bottom perp. direction | Straight | 1250 | 5 | 6.25m | 2.5 |
| GL-T1 | GF landing top | T10 | Top both directions | Straight | 700 | 14 | 9.8m | 6.1 |
| FF LANDING SLAB — 150mm (1200 × 750mm) | ||||||||
| FL-M1 | FF landing main | T10 | Bottom span direction | Straight | 850 | 9 | 7.65m | 4.7 |
| FL-D1 | FF landing dist. | T8 | Bottom perp. direction | Straight | 1250 | 5 | 6.25m | 2.5 |
| FL-T1 | FF landing top | T10 | Top both directions | Straight | 850 | 14 | 11.9m | 7.4 |
T10 Bars
Flight: ~32 kg
Landings: ~22 kg
≈ 54 kg
Landings: ~22 kg
≈ 54 kg
T8 Bars
Flight: ~15 kg
Landings: ~5 kg
≈ 20 kg
Landings: ~5 kg
≈ 20 kg
Concrete
Flight: ~0.82 m³
Landings: ~0.29 m³
≈ 1.11 m³
Landings: ~0.29 m³
≈ 1.11 m³
Total Steel
T10: 54 kg
T8: 20 kg
≈ 74 kg
T8: 20 kg
≈ 74 kg
ENGINEERING NOTES
IS 456:2000 · SP 16 · IS 875
Design: IS 456:2000 — Waist Slab Method (Cl. 33)
· Stair type: Single-flight spanning longitudinally
· Effective span: Le = 3000mm (clear + half bearing each end)
· Waist slab t = 150mm (span/20 = 138mm → 150mm adopted)
· Main bars: T10@150 parallel to slope at bottom
· Distribution: T8@200 perpendicular to span
· Top bars: T10@150 at each support (top face), L/4 extent
· Cover: 20mm — stair exposed to weather on tread surface
· Kicker block: 75mm at riser foot on each tread
· Main bars bent up at support with 90° hook, Ld ≥ 400mm
· Landing slab: T10@150 both ways (span + distribution)
· Construction: cast waist slab first, step brickwork/concrete after
· Nosing: 25mm overhang, rounded edge, anti-skid finish
· Handrail: 900mm height, provided on open side
· Stair type: Single-flight spanning longitudinally
· Effective span: Le = 3000mm (clear + half bearing each end)
· Waist slab t = 150mm (span/20 = 138mm → 150mm adopted)
· Main bars: T10@150 parallel to slope at bottom
· Distribution: T8@200 perpendicular to span
· Top bars: T10@150 at each support (top face), L/4 extent
· Cover: 20mm — stair exposed to weather on tread surface
· Kicker block: 75mm at riser foot on each tread
· Main bars bent up at support with 90° hook, Ld ≥ 400mm
· Landing slab: T10@150 both ways (span + distribution)
· Construction: cast waist slab first, step brickwork/concrete after
· Nosing: 25mm overhang, rounded edge, anti-skid finish
· Handrail: 900mm height, provided on open side
CONSTRUCTION SEQUENCE
RECOMMENDED ORDER| # | Activity | Note |
|---|---|---|
| 1 | Set out stair incline, fix soffit shuttering | Slope 34.9° |
| 2 | Fix main bars T10@150 parallel to slope | Secure to chairs 20mm |
| 3 | Fix dist. bars T8@200 crosswise | Tie at intersections |
| 4 | Fix top bars T10@150 at supports | Extend L/4 from face |
| 5 | Pour M20 waist slab monolithically | Vibrate carefully |
| 6 | Cast step risers after waist cures (7 days) | Formwork per step |
| 7 | Apply tread finish + nosing | Anti-skid required |
| 8 | Erect handrail after 28-day cure | 900mm min. height |