Wooden beams are central load-bearing elements in structural engineering. They form floor layers, carry roof structures, and connect components made of masonry or concrete. In existing buildings, wooden beams frequently meet natural stone or brick masonry as well as subsequently added concrete components. In refurbishment works, building gutting, and selective deconstruction, this interplay is crucial: elements must be separated, load transfer secured, and adjacent timber components protected against vibration, moisture, and damage. Especially for work around wooden beams, low vibration levels and precise methods have proven effective, as used in the context of concrete pulverizer or hydraulic splitter, often operated via suitable hydraulic power units.
Definition: What is meant by wooden beam
A wooden beam is a longitudinal, usually rectangular timber cross-section that transfers loads via bending and shear. It is made of solid wood (e.g., structural timber), glued laminated timber, or other wood-based materials. Wooden beams form joist layers in floors and roofs, bear at points or along lines on masonry, concrete, or steel, and are integrated into the load-bearing system via wood-to-wood, wood-to-steel, or wood-to-concrete connections. Typical tasks include taking up self-weight, live loads, and installation loads and transferring them into load-bearing walls, beams, or foundations.
Construction, materials, and cross-sections of wooden beams
Wooden beams are selected according to use, span, and environmental conditions. Common cross-sections are rectangular; for larger spans, glued laminated timber girders are used, which, through lamination, offer a favorable ratio of load-bearing capacity, stiffness, and dimensional stability. In existing buildings, softwoods with natural irregularities are common; in new construction, graded cross-sections with defined strength classes are typical.
Bearing is often achieved in masonry pockets or on steel bearing shoes. In existing structures, rebates, notches, or drillings for service runs are frequently found. These details influence load-bearing capacity and must be carefully assessed during refurbishment, gutting, or deconstruction, especially when adjacent components made of concrete or natural stone are to be selectively separated with a concrete pulverizer or hydraulic splitter.
Structural behavior and design considerations
The structural behavior is governed by bending, shear, torsion, and stability. Wood shows anisotropic properties; grain direction, moisture content, and existing cracks influence load-bearing capacity. Service and environmental conditions (moisture classes), creep and shrinkage, and durability at the bearing end are relevant.
Bending and shear
In wooden beam floors, bending is decisive. Notches at supports increase local stresses; shear checks and constructive measures (notch reinforcements, bearing timbers, steel angles) must be considered. In interventions on existing structures, the removal of bearing beddings made of mortar or concrete must be carried out in a controlled manner to avoid exacerbating notch effects.
Deflection and vibration
Serviceability is characterized by deformations and vibration behavior. The low mass of wooden beam floors leads to perceptible vibrations; additional loads, composite slabs, or shear couplings can help.
Bearings and connection details to masonry and concrete
Wooden beams often bear in masonry pockets and are in contact with brick masonry, natural stone, or concrete. Building protection starts at the bearing: capillary-breaking layers, ends exposed to air, or metallic bearing parts prevent moisture accumulation and decay.
Selective separation of adjacent components
If concrete add-ons or concrete shells in the vicinity of the wooden beams must be removed, a controlled, low vibration levels approach is recommended. A concrete pulverizer allows targeted nibbling of thinner concrete buildups, while hydraulic rock and concrete splitters create borehole-induced cracks in massive areas. This reduces secondary damage to wood fibers and masonry pockets.
Wood–concrete interfaces
For wood–concrete connections (e.g., wood-concrete composite), shear connectors, composite screws, and concrete add-ons must be handled so that the structural action is understood and temporarily secured. Before deconstruction, load transfer rerouting, bracing, and, where necessary, provisional underpinning must be planned.
Condition assessment, damage patterns, and refurbishment
Existing-condition surveys provide the basis for every measure. Moisture, biological effects, and mechanical damage are the most frequent causes of loss of load-bearing capacity.
Typical damage patterns
- Bearing-end decay due to moisture accumulation in masonry pockets
- Insect or fungal infestation with elevated moisture content
- Cracks along the grain, notch and borehole damage
- Top-heaviness from additional loads not accounted for in design
- Corrosion at metal connections with consequential impairments
Refurbishment strategies
Depending on findings, measures range from wood protection and cross-section supplementation to replacement. During accompanying deconstruction of concrete or stone components in the bearing area, a dust suppression, low vibration levels approach with a concrete pulverizer or hydraulic splitter can protect the substance of the wooden beams. Hydraulically operated methods with adapted hydraulic power pack allow finely metered forces in sensitive environments.
Deconstruction, interior demolition, and protection of wooden beams in existing buildings
Within interior demolition and selective deconstruction, the aim is to preserve wooden beam layers or expose them without damage. Procedures that minimize vibration, dust, and noise are generally advantageous—especially in occupied buildings, hospitals, or heritage-protected properties.
Work steps at a glance
- Structural analysis and specification of temporary shoring
- Exposure of bearing zones and condition assessment
- Selective separation of adjacent concrete or stone components (e.g., with a concrete pulverizer or hydraulic splitter)
- Gentle release of masonry, if necessary with controlled splitting operations
- Wood protection measures and climatic stabilization of the bearing areas
Wood–concrete composite (HBV): interventions and specifics
Wood–concrete composite decks combine wooden beams with a concrete layer on top to increase load-bearing capacity, stiffness, and building acoustics. For interventions, the composite mechanism (shear connectors, screws, dowels) must be understood. Removing local concrete parts is achieved in a controlled manner with a concrete pulverizer, while massive areas can be separated via borehole splitting using a hydraulic splitter to avoid overloading the timber flanges.
Advantages and risks
- Improved deflection and vibration behavior for the same span
- Increased fire protection and sound insulation due to the mineral layer
- Risk of uncontrolled loss of composite action in improper deconstruction
Fire protection, sound insulation, and moisture protection
Wood chars at the surface and retains a load-bearing residual cross-section behind the char. Proper planning accounts for charring rates and the requirements from usage and building class. When deconstructing adjacent mineral layers, the temporary exposure of wooden beams to moisture and temperature fluctuations must be limited.
Sound insulation
Wooden beam floors benefit from decoupling and additional load systems. The selective removal of heavy layers should be performed so that structure-borne sound is not unnecessarily excited; low vibration levels methods are advantageous here.
Tools and methods around wooden beams
The choice of tool follows the goal of precisely separating or exposing wooden beams and adjacent constructions. In practice, the following have proven successful:
- concrete pulverizer: targeted, controlled nibbling of concrete crusts, ribbed slab edges, or leveling layers without high impact impulse.
- hydraulic splitter: borehole-based splitting of massive concrete or natural stone parts in the immediate vicinity of wood to minimize vibration.
- hydraulic power pack: demand-based power supply, finely metered for sensitive existing areas.
- hydraulic demolition shear: cutting steel connections, reinforcing steel, or profiles that couple wooden beams with other components.
These methods are particularly relevant in the application areas concrete demolition and special demolition, interior demolition and cut, as well as special demolition, when confined space, heritage protection, or high protection requirements exist.
Planning, structural analysis, and workflow organization
Before measures on wooden beams, boundary conditions for structural analysis must be clarified. Load redistribution, temporary shoring, and construction stages must be confirmed on site. Clean workflow planning reduces risks and downtime.
Recommendations for the project workflow
- Early survey of the existing structure with openings at representative locations
- Definition of protection zones for wooden beams and bearing areas
- Sequential deconstruction of adjacent concrete and stone components with controlled tools
- Ongoing moisture and dust control in the work area
- Documentation of changes to the structure and acceptance of interim states
Occupational safety and legal notes
Work on load-bearing components must always be carried out with appropriate qualifications. Safety regulation, dust protection, noise control, machine safety, and fall protection must be observed. Legal requirements may vary by project and region; planners and contractors should consider the relevant standards, rules of technology, and official requirements.
Application areas and practical relevance
Wooden beams are encountered by professionals in many constellations:
- interior demolition and cut: exposing joist layers, removing cement screeds or shells in the connection area with a concrete pulverizer.
- concrete demolition and special demolition: splitting massive concrete add-ons near wood bearing zones using a hydraulic splitter to protect wood fibers.
- special demolition: work in sensitive areas (e.g., heritage protection) where minimal vibration and pinpoint separation operations are required.
- rock excavation and tunnel construction: removing historical timber support elements in the vicinity of natural stone or shotcrete requires a low-vibration approach and precise separation technology using Rock Splitters.
- natural stone extraction: touchpoints arise in buildings made of natural stone with embedded wooden beams; controlled splitting operations are helpful when exposing the bearings.