Fraunhofer Institute for Wood Research
Wilhelm-Klauditz-Institut WKI
Fraunhofer Institute for Wood Research
Wilhelm-Klauditz-Institut WKI

Quality Assessment

Testing, Monitoring and Certification (TMC)

Testing body for structural bonding

Due to the targeted reduction of carbon dioxide emissions (CO2) and the “carbon footprint“ relating thereto, wood as an environmentally-friendly material is currently gaining importance in numerous new fields of application - including the construction sector. These include applications in load-bearing and non-load-bearing timber construction as well as in the production of wood-based materials and furniture. Particularly in load-bearing timber construction, wood building materials and their constructive connections are subject to stringent requirements. In light of this, focus is being increasingly placed upon adhesives. In comparison to punctiform connections by means of screws or nails, flat adhesive bonds generally offer a better distribution of forces. Through the testing of adhesive systems, we provide a decisive contribution towards an increase in the proportion of renewable raw materials in the building and furniture industries.

The evaluation and characterization of the bonding and mechanical-technological properties of wood-based materials and wood building products is regulated by law. The Fraunhofer WKI has been accredited by the Deutsche Akkreditierungsstelle GmbH (German national accreditation body, DAkkS) as an inspection body for bondings and adhesive systems in accordance with ISO/IEC 17025. Furthermore, since 11.10.2017, the inspection body is recognized in accordance with the Landesbauordnung (regional building regulations, LBO) for adhesives for load-bearing timber construction components pursuant to PÜZ-Verzeichnis (TMC directory) Issue 2017 – Part II a, Seq. No. 3.3/4.
 

We offer our customers the following tests for adhesive systems:

For load-bearing applications, e.g.:

  • phenoplastics and aminoplastics
  • single-component adhesives on the basis of polyurethane
  • emulsion-polymerized isocyanate
  • two-component adhesive systems (2C-EP and 2C-PUR)
     

For non-load-bearing applications, e.g.:

  • thermoplastic adhesive systems
  • parquet testing
  • resistance to static load
     

Furthermore, our focus is also placed upon:

  • the evaluation and expansion of test methods for established areas of application for adhesives
  • the development of new test modes for innovative application possibilities (e.g. wood-composite systems) in close cooperation with other research facilities and industrial partners.

In addition to applied research, we offer through the WKI | AKADEMIE® a differentiated training program in the field of adhesives for load-bearing timber construction. Furthermore, our many years of experience are applied in the new and further development of adhesive systems for the production of wood-based materials and for wooden construction.

Range of Services

Building products in the Building Rules List A Part 1

SEQ. No.  DESIGNATION OF THE BUILDING PRODUCT RECOGNIZED AS INSPECTION BODY IN ACC. WITH § 25 CLAUSE 1 No. 2 NBAUO (Lower Saxony building regulations)
3.5.1 Phenoplastics and aminoplastics of Adhesive Type I for bonded load-bearing connections in and of wooden components 

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Building products with general building inspection approval in compliance with Part II a of the register of testing, monitoring and certification bodies in accordance with the state building regulations

SEQ. No. ASSOCIATED APPROVAL NUMBER DESIGNATION OF THE APPROVAL GROUP  RECOGNIZED AS INSPECTION BODY IN ACC. WITH § 25 CLAUSE 1 No. 2 NBAUO (Lower Saxony building Adhesives for load-bearing wooden components 
3.3/4 Z-9.1-… Adhesives for load-bearing wooden components

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Accredited inspections in accordance with ISO/IEC 17025

Rule type Product Details
DIN EN 204 Classification of thermoplastic wood adhesives for non-structural applications
DIN EN 205 Adhesives Wood adhesives for non-structural applications - Determination of tensile shear strength of lap joints
DIN EN 301 Adhesives, phenolic and aminoplastic, for load-bearing timber structures Classification and performance requirements
DIN EN 302-1 Adhesives for load-bearing timber structures Test methods - Part 1: Determination of longitudinal tensile shear strength
DIN EN 302-2 Adhesives for load-bearing timber structures Test methods - Part 2: Determination of resistance to delamination
DIN EN 302-3 Adhesives for load-bearing timber structures Test methods - Part 3: Determination of the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile strength
DIN EN 302-4 Adhesives for load-bearing timber structures Test methods - Part 4: Determination of the effects of wood shrinkage on the shear strength
DIN EN 302-5 Adhesives for load-bearing timber structures Test methods - Part 5: Determination of maximum assembly time under referenced conditions
DIN EN 302-6 Adhesives for load-bearing timber structures Test methods - Part 6: Determination of the minimum pressing time under referenced conditions
DIN EN 302-7 Adhesives for load-bearing timber structures Test methods - Part 7: Determination of the working life under referenced conditions
DIN EN 1245 Adhesives Determination of pH
DIN EN 12092 Adhesives Determination of viscosity
DIN EN 14080, Anhang B.2 Timber structures Glued laminated timber and glued solid timber - Requirements; Sustained loading test with cyclic climatic conditions on test specimens with loading orthogonal to glued joint for moisture-curing single-component adhesives on the basis of polyurethane and emulsion-polymer-isocyanate adhesives
DIN EN 14080, Anhang B.3 Timber structures Glued laminated timber and glued solid timber – Requirements; Delamination testing of finger joints in laminations
DIN EN 14080, Anhang C Timber structures Glued laminated timber and glued solid timber – Requirements; Testing of delamination of glued joints
DIN EN 14080, Anhang D Timber structures Glued laminated timber and glued solid timber – Requirements; Shear testing of glued joints
DIN EN 14256 Adhesives for non-structural wood applications Test method and requirements for resistance to static load
DIN EN 14257 Adhesives Wood adhesives - Determination of tensile strength of lap joints at elevated temperature (WATT'91)
DIN EN 14293 Adhesives Adhesives for bonding parquet to subfloor - Test methods and minimum requirements
DIN EN 15416-1 Adhesives for load bearing timber structures other than phenolic and aminoplastic Test methods - Part 1: Long-term tension load test perpendicular to the bond line at varying climate conditions with specimens perpendicular to the glue line (Glasshouse test)
DIN EN 15416-2 Adhesives for load bearing timber structures other than phenolic and aminoplastic Test methods - Part 2: Static load test of multiple bondline specimens in compression shear
DIN EN 15416-3 Adhesives for load bearing timber structures other than phenolic and aminoplastic Test methods - Part 3: Creep deformation test at cyclic climate conditions with specimens loaded in bending shear
DIN EN 15416-4 Adhesives for load bearing timber structures other than phenolic and aminoplastic Test methods - Part 4: Determination of open assembly time for one component polyurethane adhesives
DIN EN 15416-5 Adhesives for load bearing timber structures other than phenolic and aminoplastic Test methods - Part 5: Determination of conventional pressing time
DIN EN 15425 Adhesives One component polyurethane for load bearing timber structures Classification and performance requirements
DIN EN 16254 Adhesives Emulsion-polymerized isocyanate (EPI) for load-bearing timber structures – Classification and performance requirements