Strip-out technology describes controlled, selective deconstruction within existing structures. The aim is to remove components in the existing fabric with precision, preserve load-bearing structures, and create the basis for refurbishment, repurposing of structure, or subsequent partial demolition. The focus is on low-vibration, low-emission, and precise methods that work in confined spaces, sensitive environments, and during ongoing operations. In practice, this mainly involves hydraulic tools such as concrete demolition shears as well as hydraulic rock and concrete splitters, supplied by compact hydraulic power units. They enable quiet, controlled removal, separation, and splitting of concrete, masonry, natural stone, and metal—typical for the application areas concrete demolition and special demolition, strip-out and cutting, rock demolition and tunnel construction, natural stone extraction, as well as special operations.
Definition: What is meant by strip-out technology
Strip-out technology refers to the systematic removal of non-load-bearing and selected load-bearing components in buildings and civil engineering structures. It includes dismantling of fit-out, installations, metal structures, and locally confined concrete areas through to cutting off reinforced components. It is characterized by detailed planning, coordination with structural analysis and building physics, and the use of controlled cutting, crushing, and splitting methods. Strip-out differs from full demolition through its high selectivity, source-separated material sorting, and the preservation of the primary load-bearing structure. Hydraulic concrete demolition shears and stone and concrete splitters are considered the methods of choice when low vibration levels, reduced noise, and maximum precision are required.
Main processes and work phases in strip-out technology
Strip-out typically follows a structured sequence: from the condition survey including hazardous substance investigation, through exposing and securing, cutting and splitting, to source-separated material logistics. In the intervention phase, concrete and masonry are removed in sections with concrete demolition shears or pre-fractured with stone and concrete splitters with low vibration, before reinforcement and embedded parts are cleanly cut with combination shears, multi cutters, or steel shears. Compact hydraulic power packs provide the necessary drive power, even where large machines cannot gain access. The result is controlled cut and fracture edges, minimal secondary damage, and optimized conditions for subsequent works.
Tools and systems in strip-out technology
Hydraulic tool systems are established in strip-out because they deliver high forces in a compact form factor, enabling work in tight, sensitive interior spaces. Manufacturers such as Darda GmbH develop coordinated components for this: hand-held or carrier-adaptable shears and splitting cylinders as well as high-performance hydraulic power packs with demand-oriented flow rate.
Concrete demolition shears: controlled “biting” of concrete
Concrete demolition shears crush concrete components by applying high compressive forces and produce defined fracture surfaces. They are predestined for the selective removal of walls, slab edges, upstands, or foundation heads, especially in reinforced concrete. Advantages include lower vibration compared with percussion tools, reduced noise, and precise, layer-by-layer working. Typical applications are interior demolition during ongoing operations, work on sensitive structures, and exposing reinforcement prior to cutting with steel shears.
Stone and concrete splitters: low-vibration splitting
Stone and concrete splitters operate according to the hydraulic wedge principle. After drilling a few precisely positioned holes, splitting cylinders are inserted and the component is opened in a controlled manner. The method is suitable for massive cross-sections, thick foundations, pier heads, or densely reinforced concrete where sawing or milling methods reach their limits. A fracture-mechanically guided crack is created, enabling dismantling into manageable pieces—ideal in confined areas or where strict vibration limits apply.
Hydraulic power packs: energy supply for compact tools
Hydraulic power packs deliver pressure and flow for shears, splitting cylinders, and cutters. For interior work, low-noise, emission-free solutions are advantageous. Important criteria include starting current, speed control, oil temperature management, quick couplings, and hose management for safe, trip-free routing. The interaction of power pack and tool determines cycle times, cutting speed, and the sustained force delivery under real jobsite conditions.
Combination shears, multi cutters, and steel shears
These tools cut metals such as reinforcing steel, sections, lines, and frame constructions. Combination shears often integrate cutting and crushing contours for versatile tasks, while steel shears are designed for high cutting forces on massive cross-sections. Multi cutters offer flexibility for varying material thicknesses. In combination with concrete demolition shears, a clean workflow emerges: first loosen concrete, then cut metal—precise, predictable, material-appropriate.
Tank cutters for special separation tasks
During the deconstruction of vessels, silos, and tanks, tank cutters enable controlled separation cuts on cylindrical or conical geometries. Decisive factors include minimizing sparks, safe fixation, and emptying and inerting the vessels in accordance with the applicable technical rules. Use typically occurs in special operations, combined with cordoning and ventilation concepts.
Applications and typical scenarios
Strip-out technology is used in various environments. The selection of methods depends on material, accessibility, structural requirements, and environmental constraints.
- Concrete demolition and special demolition: Removal of column heads, cantilever arms, shear walls; concrete demolition shears for edge removal, stone and concrete splitters for massive cross-sections.
- Strip-out and cutting: Removal of interior walls, shafts, staircases; cutting reinforcement and embedded parts with steel shears and combination shears.
- Rock breakout and tunnel construction: Splitting rock noses or protrusions with splitting cylinders, low-vibration near sensitive infrastructure.
- Natural stone extraction: Gentle release of blocks through targeted splitting, minimizing crack formation outside the intended line.
- Special operations: Work in hospitals, laboratories, listed buildings, or alongside ongoing production with strict limits on noise, dust, and vibration.
Method selection: cutting, crushing, splitting
The decision between cutting, crushing, and splitting depends on member thickness, degree of reinforcement, required precision, and boundary conditions.
- Cutting: Suitable for exact kerfs but often requires water and sludge management; sensibly combined with steel shears for reinforcement.
- Crushing with concrete demolition shears: Flexible, low-vibration, and dry; good for sectional removal and producing defined fracture edges.
- Splitting: Particularly economical for massive cross-sections; few drill holes, controlled crack path, minimal secondary damage.
On many projects, the hybrid method leads to the goal: pre-cut, split locally, then remove with concrete demolition shears and separate metal fractions with shears.
Planning, structural analysis, and risk assessment
Robust strip-out planning starts with an as-built analysis, including drawings, rebar detection, and material investigation. Interventions in load-bearing components are to be coordinated with structural analysis. Load transfer, temporary shoring, demolition sequence, and load paths must be defined. For sensitive environments, vibration, dust, and noise concepts are to be planned. Interventions should proceed step by step, with trial steps and continuous monitoring of deformations.
Environment and occupational safety
Protecting people and the environment has priority. Measures include dust suppression (mist, localized wetting), noise reduction, air exchange indoors, separate material logistics, and low-residue working methods. Hydraulically operated concrete demolition shears and splitters support a low-emission execution. Personal protective equipment, safe hose routing, pressure relief, tool changes in accordance with the operating manual, as well as cordoned and signal zones must be considered. Legal requirements and the rules of technology depend on the situation; binding statements require a project-specific review.
Logistics, accessibility, and energy supply
Strip-out work often takes place across floors, in shafts, or in densely occupied rooms. Compact, modular tools that can be transported by elevator or stairs are advantageous. Hydraulic power packs should be selected to match the available power supply, with reserve for peak loads. Hose lengths, couplings, and carrying aids must be planned to ensure freedom of movement, ergonomics, and safety.
Quality assurance and documentation
Documented demolition sequences, test protocols, and fixed photo positions ensure traceability. Markings of cut and split lines, sign-offs after intermediate checks, and continuous material flow documentation support schedule, cost, and sustainability. Digital as-built data and continuously updated plans help minimize surprises and maintain pure material streams.
Practical tips for efficient strip-out
- Check member behavior in advance: locate rebar, analyze load paths, define demolition sequence.
- Select the right tool: concrete demolition shears for controlled removal, stone and concrete splitters for massive cross-sections, shears for metal separation.
- Tune the hydraulics properly: size power pack capacity, hose cross-section, and couplings to the tool demand.
- Optimize the drilling pattern for splitting: adapt hole spacing and depth to member thickness, reinforcement, and the desired fracture line.
- Work in sections: small, controlled steps reduce risks and make material logistics easier.
- Integrate dust suppression and noise control: plan localized wetting, quiet methods, enclosures, and air handling.
- Separate metals early: pure material streams improve recycling quality and reduce disposal costs.
- Check tool condition: regularly inspect and service blades, jaws, cylinders, and couplings.
Common sources of error and how to avoid them
- Underestimated reinforcement: plan for preliminary investigations and trial steps; have a combination of concrete demolition shears and steel shears ready.
- Intervention steps that are too large: better work in small sections to avoid crack propagation and uncontrolled breaks.
- Missing shoring: install temporary supports before loosening load-bearing areas.
- Incorrect hydraulic tuning: match pressure/flow to tool requirements and line lengths to avoid performance losses.
- Insufficient dust and noise precautions: combine technical and organizational measures instead of reacting only after exceedances.
Standards, rules, and permits at a glance
Depending on the project and location, technical rules, occupational safety and environmental requirements, as well as building and permitting regulations apply to strip-out work. These include requirements for emissions, vibrations, protection from falling parts, waste separation, and transport. These points must be clarified on a project-specific basis; compliance with relevant rulebooks and official requirements should be coordinated with those responsible at an early stage.