BS EN 15425:2017

What is BS EN 15425 - Polyurethane (PUR) adhesives  about ?

BS EN 15425 is an international standard for adhesives that specifies the test methods which helps in determining the polyurethane (PUR) adhesives.  

BS EN 15425 establishes a classification for one component polyurethane (PUR) adhesives according to their suitability for use in load-bearing timber structures in defined climatic exposure conditions. BS EN 15425 specifies performance requirements for such adhesives for the factory manufacture or factory-like manufacturing of load-bearing timber structures only. 

BS EN 15425 specifies the performance of adhesives for use in an environment corresponding to the defined conditions. 

Note: The performance requirements of BS EN 15425 apply to the adhesives only, not to the timber structure. BS EN 15425 does not cover the performance of adhesives for on-site gluing (except for factory-like conditions) nor the production of wood-based panels, except solid wood panels, or modified and stabilized wood with considerably reduced swelling and shrinkage properties, e.g., such as acetylated wood, heat treated wood and polymer impregnated wood. 

Note 2: BS EN 15425 is primarily intended for the use of adhesive manufacturers and for the use in timber structures bonded with adhesives, to assess or control the quality of adhesives. The requirements apply to the type testing of the adhesives. Production control activities are outside the scope of this European Standard. 

Who is BS EN 15425 - Polyurethane (PUR) adhesives for ?

BS EN 15425 on adhesives is useful for: 

• Constructors of buildings
• Civil engineers  
• Architects 
• Manufacturers of timber structures 
• Interior designers 

Why should you use BS EN 15425 - Polyurethane (PUR) adhesives ?

Polyurethane adhesives are also known to retain relative flexibility. This Polyurethane is useful in absorbing the stress and dampen the vibration to which they are subjected. By using BS EN 15425 you can stick or join the timber structures by applying the Polyurethane (PUR) adhesives on load-bearing timber structures. 

BS EN 15425 provides the requirements for test methods of adhesives. The test method are as follows:  

• Determination of longitudinal tensile shear strength 
• Determination of resistance to delamination 
• Determination of tensile strength perpendicular to the glue line after climatic treatment (acid damaged test)
• Determination of the effect of wood shrinkage on the shear strength 
• Static load test of multiple glue line specimens in compression shear 
• Creep deformation test with specimens loaded in bending shear 
• Long-term sustained load test at cyclic climate conditions with specimens loaded perpendicular to the glue line (“Glass house test”) 

BS EN 15425 also helps in determining the working properties of adhesives. These working properties are as follows:  

• Determination of initial viscosity under reference conditions 
• Determination of open assembly time under reference conditions 
• Determination of pressing time under reference conditions 

By applying BS EN 15425, you can classify the polyurethane (PUR) adhesives and determine and evaluate the performance of the adhesives for load-bearing timber structures.  

What’s changed since the last update ?

BS EN 15425:2017 supersedes BS EN 15425:2008. BS EN 15425:2017 includes some technical changes with respect to BS EN 15425:2008. These include: 

• A new classification system has been introduced. 90 °C test temperature and 1 mm glue line thickness are included in the test program in Clause 4. Adhesives tested for working properties according to Clause 7 will be marked with a “w” in the end of their designation code 
• A new test method is given in 5.8: Long-term sustained load test at cyclic climate conditions with specimens loaded perpendicular to the glue line (Glass house test – EN 15416-1:2017) 
• The necessary duration times for the test given in 5.7 have been reduced for glue line thickness 0,3 mm (General purpose adhesives). Identical duration times have been introduced for the new class “Special purpose adhesives” with 0,5 mm glue line thickness in test 
• EN 15416-2:2007, Adhesives for load bearing timber structures other than phenolic and aminoplastic — Test methods — Part 2: Static load test of multiple bond line specimens in compression shear has been introduced to the EN 302 series as EN 302-8:2017