The stair flight, as a continuous sequence of steps between two levels or landings, forms the functional heart of a stairwell. It connects floors, provides access to structures, and serves as an escape and rescue route in emergencies. In planning, construction, maintenance, and deconstruction, the stair flight acts as an independent structural element with clear geometric, structural, and building physics requirements. Especially for massive reinforced concrete stairs, it plays a central role in concrete demolition and special demolition as well as in building gutting and cutting, because geometry, reinforcement, and support conditions decisively determine the choice of methods and tools—up to and including concrete pulverizer or hydraulic splitter.
Definition: What is meant by stair flight
The stair flight (also stair run) is the inclined portion of a staircase consisting of a series of treads (with or without risers) that connects two levels or landings. It is characterized by rise (height per step), going (depth per step), flight width, inclination, and the number of steps. Structurally, a stair flight can be executed as a cast-in-place concrete element, as a precast or semi-precast element, or as a steel or timber construction. In solid construction, support typically occurs on walls, landings, or stair cores; load transfer takes place longitudinally to the lower support. In existing structures, the type of supports, the composite with adjacent elements, and the reinforcement govern planning, refurbishment, or deconstruction.
Structure and geometry of a stair flight
A typical stair flight consists of an inclined load-bearing slab (flight slab) with applied or integrated steps, connected at the start and end to walls, slabs, or landings. Decisive are harmonious proportions of rise and going, a flight width suited to use, and secure support details for load transfer, acoustics, and fire protection. In reinforced concrete, longitudinal and transverse reinforcement take up bending and shear forces; in precast construction, built-in components for assembly and composite with cast-in-place concrete are common.
Construction details
- Start and end of flight: connection to ground slab, slab edge, or landing; often with reinforcement anchors, support corbels, or built-in components.
- Steps: formed monolithically with the flight slab or as applied elements; surface slip-resistant, wear-resistant, and acoustically optimized.
- Support: line or point bearing depending on construction method; elastic interlayers can decouple structure-borne sound.
- Stringers and girders: used for stiffening at larger spans or for architectural requirements.
Dimensions and proportions
- Rise and going follow the ergonomic step rule; excessive deviations impair safety and comfort.
- Flight width depends on use, escape route width, and frequency.
- Landings subdivide long flights, provide rest, and allow direction changes.
Materials and execution
- Cast-in-place concrete: high form freedom, integral connections, good fire resistance.
- Precast/semi-precast: fast installation, defined exposed surfaces; connection reinforcement and grout joints are structurally decisive.
- Steel constructions: low self-weight, fast disassembly; observe corrosion protection.
Stair flight in solid construction: cast-in-place and precast
In solid construction, the stair flight is usually made of reinforced concrete. Cast-in-place flights are poured in a single operation with flight slab and steps and benefit from continuous reinforcement and a robust composite with landings and walls. Precast flights are factory-made, transported to site, and set on prepared supports; grouted connections and connection reinforcement ensure load transfer. For later deconstruction, it matters whether there is a continuous composite with the stair core or defined separation joints are present.
Typical connection details
- Fixing to landings with connection reinforcement
- Support on corbels with elastomer bearings
- Keyed joints and grout with high-strength mortar
Stair flight in existing buildings: condition assessment and damage patterns
The service life of a stair flight is influenced by use, climate, and construction method. Before refurbishment or deconstruction, investigations include visual inspection, measurement of element thickness, detection of reinforcement layout, verification of concrete cover, and, where applicable, tests for carbonation or chlorides. Common findings are edge spalling, cracks due to restraint or settlement, wear of treads, or corroded handrail-post connections. Findings and intended use determine repair, strengthening, or deconstruction in sections.
Deconstruction of stair flights: methods and tools
For deconstruction, the principle is selective, controlled demolition. The goal is to safely redirect loads, protect adjacent elements, and minimize emissions. In building gutting and cutting as well as in concrete demolition and special demolition, different methods are used depending on element thickness, reinforcement, and accessibility.
Cutting, breaking, splitting
- Concrete pulverizer: For targeted biting and size reduction of steps, edges, and the flight slab; advantageous where stairwells are well accessible and for sectional demolition. Comparable devices include Concrete crushers.
- Hydraulic splitter or stone splitting cylinders: Hydraulic, nearly low-vibration splitting via borehole patterns; suitable for separating massive flight slabs from adjacent walls or for controlled division of large elements, often using hydraulic rock and concrete splitters.
- Combination shears and multi cutters: For mixed constructions with concrete and steel components, e.g., stairs with steel stringers or embedded sections.
- Steel shear: For separately cutting exposed reinforcement, handrail posts, or steel stringers after removal of concrete.
Hydraulic supply and ergonomics
Handheld tools are supplied with pressure oil by hydraulic power pack. In stairwells, compact hydraulic power units and lightweight hydraulic hose line are advantageous to work safely in confined spaces and keep carrying distances short.
Sequence of a controlled deconstruction
- Structural assessment and definition of load paths; securing adjacent elements.
- Creation of separation cuts and splitting boreholes at the start, end, and along joints.
- Progressive release of the flight: preferably from the upper landing downward, with controlled lowering or division into manageable pieces.
- Exposure and targeted cutting of reinforcement (e.g., with steel shear or multi cutters).
- Removal, sorting by material fractions, and preparation for recycling.
Occupational safety, emissions, and protective measures
In stairwells, confined space, fall edges, and traffic routes coincide. Measures against dust, noise, shocks, and vibration are therefore essential. Hydraulic concrete pulverizer and hydraulic splitter often enable a lower-emission approach compared to percussive methods. Shoring, guard opening protection, and landing edges must be secured; the load-bearing capacity of temporary supports must be verified. Legal requirements on occupational and environmental protection must be observed in their current versions.
Stair flight in infrastructure and underground construction
Beyond conventional buildings, stair flights are also common in shafts, plant rooms, transport structures, or as escape stairs in tunnel structures. Here, restricted access, limited ventilation, and safety requirements determine the choice of methods. For deconstruction underground, compact hydraulic hand tools with precise cutting and splitting performance are advantageous to dismantle elements in small segments and to manage long transport routes through narrow access points.
Planning modernization or deconstruction
Good preparation reduces risks and costs. In addition to as-built drawings, reinforcement scanning, thickness measurements, and probes help. The deconstruction plan defines interfaces (e.g., separation joints to the stair core), sequence, anchorage points, and lifting operations. For modernizations—e.g., accessibility, new flight widths, or altered escape route requirements—material selection, surfaces, and acoustic decoupling influence execution.
Sustainability and resource conservation
Selective deconstruction with clean separation facilitates material recycling: concrete debris can be processed into recycled aggregates, reinforcing steel returned to the metal cycle. Methods with low energy use and reduced emissions—such as hydraulic splitting or targeted size reduction with concrete pulverizer—support resource-conserving processes and protect adjacent elements that remain in use.
Key terms and dimensions at a glance
- Rise (h): vertical height per step; affects exertion when walking.
- Going (a): tread depth in the direction of travel; determines step quality.
- Flight width: clear width of the stair flight between boundaries.
- Start/end of flight: beginning and end of the flight; connection to landings or floors.
- Landing: horizontal interruption of a flight for rest or change of direction.
- Riser/tread: vertical or horizontal step element.
- Stringer/girder: lateral or bottom stiffening to ensure load-bearing capacity.
Typical interfaces in the stairwell
Stair flights are embedded in a complex environment: walls, slabs, elevator shafts, service shafts, and railings interlock. For refurbishment or deconstruction, joints, support points, and railing connections are the key interfaces. In mixed constructions—such as steel stringers with concrete treads—separate processing with steel shear and concrete pulverizer streamlines the workflow. In special-use situations with sensitive surroundings, low-vibration methods and quiet hydraulic power packs are particularly useful.