B11 · Intermediate · 1–2 hours
BS 8110 — stair flight and landings
Single flight spanning between landings: inclined self-weight, 15% span/d increase (3.10.2.2), maximum moment at zero shear, steel, deflection and shear.
Tool: Education preview · Lesson: In preparation · Example: Built awaiting check · Workbook: Not applicable · Assessment: Not started
Outstanding before release: Engineering checker to verify clause mapping against BS 8110-1 and sign off v0.1.0. Cross-checked against TCC RCC71 Stair Flight & Landing (see evidence).
Sources
| Role | Source | Note |
|---|---|---|
| Primary | BS 8110-1:1997 (+A1–A3): 3.10.1 (loads, effective span); 3.10.2.2 (span/depth +15% where flight > 60% of span); 3.4.4.4; 3.4.6; 3.5.5 (shear); Table 3.25 | Withdrawn standard — education and legacy checks only (mapping awaiting checker verification) |
| Supporting | Cross-check reference: The Concrete Centre RCC71 Stair Flight & Landing (external tool; not used in the implementation) | Comparison evidence only (mapping awaiting checker verification) |
"Primary" marks the governing clause for this exercise; "contextual" marks related clauses; "supporting" marks the design-method or data source outside the CDC. A CDC chapter mapping does not mean the CDC contains the equation used.
Prerequisites: B01 BS 8110 — one-way solid slab · Topics: Reinforced concrete
Lesson
Lesson in preparation. No content is published until it has been written and reviewed.
Calculator
Purpose: Flexural design of a straight flight spanning with its landings between two supports.
Model: Simply supported over L = a + b + c (on plan). Loads on plan: landings γh + finishes; flight γw/cosθ + γ·riser/2 + finishes. Maximum moment at zero shear.
Units: N, mm, kN, kNm; stresses in N/mm² Ranges: fcu 25–50 N/mm²; fy 250 / 460 / 500; βb 0.7–1.0
Equations: θ = atan(riser/going) ; n = 1.4G + 1.6Q per segment ; M = max of the shear-zero moment ; d = thickness at max moment − cover − Ø/2
Clauses: 3.10.1 (loads, effective span); 3.10.2.2 (span/depth +15% where flight > 60% of span); 3.4.4.4; 3.4.6; 3.5.5 (shear); Table 3.25
© 2026 QP Academy. Original calculation software implementing BS 8110-1:1997 (+A1, A2, A3). BS 8110 is WITHDRAWN (superseded by BS EN 1992-1-1 and, in Singapore, SS EN 1992-1-1). For education and for checking legacy designs only — not for new design submissions.
Not covered: Cantilever, spiral or helical stairs; stairs spanning sideways; Landing supports part-way along landings; point loads
Version 0.1.0 Draft
EDUCATION PREVIEW — NOT YET INDEPENDENTLY CHECKED. Education preview: this calculator has not yet been independently checked by an engineer. Use for learning only — not for engineering use. Outputs are stamped and must not be used for engineering work.
Excel workbook
The workbook is available with the calculator once this version is released.
Exercises
Assessment in preparation.