Contact:

Analysis of structural defects / Endoscopy / Characterisation of infestations:
DI Florian Tscherne (Ext. -15, Email)
DI Dr. Gerhard Grüll (Ext. -61, Email)

Characterisation of infestations:
Mag. Notburga Pfabigan (Ext. -23, Email)

Analysis of structural defects / Evaluation of timber constructions:
DI Dr. Andreas Neumüller (Ext. -692, Email)

Structural endoscopy: drilling of a timber component
Investigation for cavities and and measurement of ceiling constructions
Investigation of the condition of the wood

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Analysis of structural defects / Endoscopy

This specialised division called analysis of structural defects / endoscopy is focused on the damage assessment of construction works, the investigation and development of new methods for monitoring, non-destructive evaluation and predictive modelling of the future state of a building. In the area of structural endoscopy, experts from Holzforschung Austria assess the damage caused in buildings by the infestation of wood-destroying fungi and insects and prepare expert’s reports on their findings.

 

Research and development

Building diagnostics

All building materials are subject to undetected aging processes due to weathering and climatic conditions as well as to changes in the utilization of a building. The current research project focuses on questions pertaining to the analysis of the state of a building, monitoring and assessing the current state and the future state based on simulation and modelling of alteration since suitable methodology, techniques, expertise and know-how are lacking. Renovation methods are evaluated for their efficiency and are adapted to meet today’s requirements by incorporating newly developed connectors and connection techniques.

Investigation of adhesive bonded timber joints

Investigations using microscopy of bondlines provide information on the penetration of the adhesive into the wood substrate and the bondline formation for different adhesive types, adhesive spreading rates and surface quality of the wood. Microscopy-based investigations are performed on finger joints in order to determine crack initiation and crack growth processes under tensile loading.

Additional services

Investigations of easily accessible wooden components:

If a wooden component is easily accessible, an expert can assess its state by evaluating the wood via the latter’s appearance, texture, smell and impact resistance to strikes performed with an axe or hammer. Accurate assessments of the state of large-scale structural components can be performed. For such purposes large sections of the components may have to be exposed. As a result temporary accommodation for inhabitants may have to be provided. Range of applications:

  • Roof structures
  • Ceilings consisting of beams or partially sawn logs (if rendered freely accessible)
  • In case of clearly visible damage where substantial sections will have to be exposed
  • For all other easily accessible wooden components

Structural endoscopy:

Structural endoscopy represents a minimally invasive investigation method for cavities and ceiling constructions. A full-length hole is drilled through the cross section of a timber component. The experienced expert can determine the condition the wood is in from the resistance experienced during the drilling operation and from the consistency of the bore chips. Furthermore, conclusions about other building materials (e.g. steel beams, concrete, brick) can be drawn from the different levels of resistance experienced during the drilling operation. Range of applications:

  • Ceilings consisting of beams
  • Ceilings structures which cannot be made accessible from on top (e.g. inhabited rooms, valuable parquet flooring)

Characterisation of infestations:

It is crucial to characterise the nature of an infestation in order to devise a suitable curative treatment or method.  Here the primary focus lies on wood-destroying fungi and insects.

  • Wood-destroying fungi regularly encountered in buildings: Dry rot fungus (Serpula lacrymans), Cellar fungus (Coniophora puteana), White polypores (Poria spp.) and Gill polypores (Gloeophyllum spp.). Upon request, an infestation by Dry rot fungus can be determined via DNA-analysis in the laboratory of Holzforschung Austria.
  • Most commonly encountered wood-destroying insects: Old house borer (Hylotrupes bajulus), Common furniture beetle (Anobium punctatum) or the Lyctid beetles (Lyctus spp.).

Expert’s reports:

When structural defects are encountered expert’s reports with the following emphases can be prepared:

  • Evaluation of the current state and determination of the remaining load bearing capacity of timber constructions and connectors, in particular of structural timber components
  • Structural endoscopy and characterisation of the infestation

The experts of Holzforschung Austria have accumulated experience from numerous cases of structural defects and are constantly in contact with architects, structural designers and pest control services.

Special facilities

  •  Endoscope
  • Wood moisture meter with long, insulated electrodes for measurements at large depths of wooden cross-section (e.g. wooden ceiling structures)
  • Light microscope
  • PCR – Determination of wood-destroying fungi by DNA-analysis
  • Several universal testing machines

Additional information can be found at:

Wood protection

Timber Engineering

Structural analysis