Demolition methods encompass all systematic approaches used to control and deliberately separate, release, or downsize structures, concrete elements, steel frameworks, and rock formations. Modern approaches aim for safety, low emissions, precise material separation, and a high recycling rate. Today, the focus is on mechanical and hydraulic techniques such as concrete pulverizers, splitting technology with hydraulic rock and concrete splitters, and shearing and cutting methods. Darda GmbH develops tools and power units for these applications, used in typical fields such as concrete demolition and special demolition, building gutting and cutting, rock excavation and tunnel construction, natural stone extraction, and special deployments.
Definition: What is meant by a demolition method
A demolition method refers to the entirety of technical techniques and regulated procedures used to deconstruct buildings or natural rock bodies in a controlled and planned manner. This includes mechanical methods (crushing, shearing, splitting), cutting methods (sawing, separating, drilling), as well as supplementary processes of construction logistics, material separation, and disposal. In contrast to indiscriminate teardown, qualified deconstruction aims to selectively detach components, treat hazardous substances separately, control structural responses, and minimize environmental impacts such as dust, noise, and vibrations.
Selection of the demolition method: criteria and framework conditions
The choice of a suitable demolition method is based on technical, organizational, and environmental factors. Key criteria include the structural system, material types (concrete, reinforced concrete, masonry, steel), member thicknesses, reinforcement ratios, the surrounding sensitivity to vibrations, space constraints, working heights, emission limits, schedule and budget, and the targeted material separation. Methods using concrete pulverizers or stone and concrete splitters are favored when low-vibration and low-dust operation is required or when precise partial deconstruction is needed in confined areas. Hydraulic power packs supply handheld or attachable tools with the required energy and allow a flexible, mobile way of working.
Mechanical methods in concrete demolition
Mechanical methods are among the core techniques of deconstruction. They range from removing entire members to selectively extracting individual segments. Crushing and shearing processes are particularly common, as they operate without thermal input and integrate well into selective deconstruction concepts.
Concrete pulverizers in selective deconstruction
Concrete pulverizers crush concrete and separate reinforcing steel from the concrete matrix. They operate with low vibration levels, enable controlled intervention in slabs, walls, beams, and columns, and facilitate the clean separation of concrete and steel. Depending on member thickness, handheld, hydraulically operated pulverizers (supplied by hydraulic power packs) or tong-like excavator attachments are used. Advantages include fine force metering, reduced secondary damage to adjacent components, and the ability to work in sensitive areas with strict noise control requirements. Limitations arise in extremely heavily reinforced cross-sections or very large member thicknesses, where upstream or downstream cuts, core drilling, or splitting operations are required.
Combination shears, steel shears, and Multi Cutters
Combination shears unite crushing and shearing properties, allowing switching between breaking concrete and cutting steel with a single tool. Steel shears are used especially for steel structures, beam sections, and thick reinforcement. Multi Cutters offer high flexibility when separating sections, pipes, and light steel components. The selection depends on material thickness, accessibility, and the required cut. For a safe process, a clear cut sequence must be defined to control load redistribution.
Splitting technology: stone and concrete splitters
Stone and concrete splitters apply hydraulically generated pressure to pre-drilled core holes and split the material along defined fracture planes. This method is particularly low-vibration and suitable for deconstruction in sensitive environments, such as near historic facades, laboratories, hospitals, or occupied existing buildings. Rock wedge splitter cylinders transfer forces in a controlled manner into the borehole, create directed cracks, and allow the stepwise detachment of large blocks. Combined with concrete pulverizers, the process can be made efficient: first split to weaken the section, then crush and transport. Hydraulic power packs provide the mobile energy supply for splitters and pulverizers and enable a high work rhythm at constant working pressure.
Rock excavation and tunnel construction
In rock mechanics, splitting technology demonstrates its strengths: controlled crack guidance, low emissions, and high occupational safety. In tunnel and adit construction, work is often carried out in recurring cycles: drilling, splitting, removal, securing. Where blasting works are not possible or not permitted, hydraulic splitters offer a reliable alternative. When opening disturbed zones or widening cross-sections, concrete pulverizers and combination shears can be used additionally, for example to remove linings or process fitting parts.
Cutting methods: sawing, drilling, separating
Cutting methods such as wall saws and wire saws, saw cuts, and core drilling create precise separation faces with clearly defined geometry. They are often used as preparatory steps before mechanical demolition to decouple load paths or to enable controlled element lifting. Multi Cutters can additionally take on separating work on light steel components. Tank cutters are considered for cold cutting of vessels and pipelines when sparks or thermal input must be avoided.
Tank cutters in special applications
Tank cutters are used to open vessels, silos, and pipelines in a controlled manner or to cut them into segments. In areas with potentially flammable media, low-spark, cold methods are used. Organizational measures such as gas-free measurements, inerting, and continuous monitoring are integral to safe operations. In combination with steel shears and concrete pulverizers, fasteners, built-ins, and adjacent components can be removed efficiently.
Work organization and process steps in deconstruction
A structured workflow improves safety, quality, and schedule adherence. Typical steps are:
- Investigation and planning: structural diagnostics, material and hazardous substance registers, structural analysis
- Preparations: site setup, protective measures, utility power isolation, safeguards
- Building gutting and cutting: selective removal of non-load-bearing components, separation cuts and drilling
- Structural deconstruction: mechanical removal with concrete pulverizers, combination shears, splitters
- Sorting and recycling: clean separation of concrete, steel, wood, plastics
- Follow-up work: surface cleanup, joint creation, documentation
Building gutting and selective removal
In building gutting, handheld hydraulic tools are advantageous due to their compactness and controlled force application. Concrete pulverizers crush window parapets, light beams, and wall panels, while stone and concrete splitters prepare massive zones. A clear sequence of cuts and splits reduces residual stresses and prevents uncontrolled edge breakouts.
Minimizing emissions: dust, noise, vibrations
Deconstruction methods are increasingly selected based on emission criteria. Hydraulic pulverizers and splitters typically operate quieter and with lower vibrations than percussive tools. Dust can be limited by water spray, local dust extraction, and short cycles. For sensitive neighboring buildings, special requirements apply to vibrations; here, splitting technology and controlled crushing with concrete pulverizers are often the first choice.
Safety and legal aspects (general)
Safe demolition work requires forward-looking planning, adherence to standards and local regulations, and trained personnel. Hazard analysis is standard, as are permits for work at height, under load, or in ATEX zones, along with regular equipment inspections. For cutting vessels, additional measures such as gas-free measurements and continuous monitoring are common. The information in this text is general and does not replace case-specific evaluation.
Typical sources of error and practical tips
- Insufficient preliminary investigation: identify material transitions, cavities, and stresses at an early stage.
- Wrong tool selection: concrete pulverizers for crushing removal, splitters for low-vibration pre-break, shears for targeted steel cuts.
- Inappropriate drilling patterns when splitting: match hole diameter, depth, and spacing to member thickness and desired crack path.
- Missing cut sequence: preliminary separations at nodes reduce restraint and prevent uncontrolled redistributions.
- Neglecting hydraulics: match hydraulic pressure, flow rate, and hose lengths to tool demand; service hydraulic power packs regularly.
Examples from the fields of application
- Concrete demolition and special demolition: partial deconstruction of an existing slab with saw cuts, followed by crushing with concrete pulverizers and clean steel recovery.
- Building gutting and cutting: opening wall panels for new installations via core drilling and a handheld concrete pulverizer during ongoing building operations.
- Rock excavation and tunnel construction: cross-section widening by drilling and splitting with rock wedge splitter cylinders, followed by finishing work on lining parts with combination shears.
- Natural stone extraction: winning raw blocks by controlled splitting along natural joints, reduced brittleness through adapted drilling patterns.
- Special deployment: cold separation of tank segments with a tank cutter and subsequent dismantling with a steel shear, accompanied by monitoring and safeguarding measures.
Equipment, power supply, and logistics
The performance of a method depends significantly on the appropriate energy supply and site logistics. Hydraulic power units for deconstruction provide mobile operating pressure and flow for stone and concrete splitters, concrete pulverizers, combination shears, and Multi Cutters. Hose management, secure quick couplings, sufficient hose lengths, and protection of lines are crucial in confined existing structures. For material transport, clear routing with intermediate storage areas for sorting is recommended.
Hydraulic power packs as the central energy source
Hydraulic power packs enable the operation of multiple tools with matched pressure stages. Advantages include compact designs for interior spaces, low noise emission, and easy maintenance. Correctly matching pressure, flow, and tool characteristics ensures that pulverizers, splitters, and shears achieve their rated performance efficiently.
Quality control and documentation
Quality in deconstruction is reflected in accurate separation cuts, defined crack paths when splitting, minimal secondary damage, and cleanly separated material streams. Documented are measurements for vibrations, dust, and noise, the progress of material separation, and evidence of recycling. A handover-ready condition includes prepared connection surfaces, clean member edges, and secured transport away from the site.
Outlook: developments in demolition technology and deconstruction
The future of demolition methods is shaped by digitalization, low-emission drives, and even more precise tools. Electrified hydraulic power packs, remote-controlled applications in hazardous areas, and adaptive controls increase safety and efficiency. Methods such as concrete pulverizers and stone and concrete splitters remain central building blocks, as they work in a controlled, selective, and resource-efficient manner and fit into integrated deconstruction concepts.