1.1 This specification covers adhesives suitable for the bonding of wood, including treated wood, into structural wood products for general construction or other uses where a high-strength, durable adhesive bond is required.

1.2 This specification includes test methods that may be referenced by specific product standards for the evaluation and approval of structural wood adhesives. Methods are included to evaluate adhesives intended for use in exterior exposure, which are characterized and defined by two distinct service classes as described in 1.3.

Note 1 - Consult the Commentary in Appendix X1 regarding the intent and limitations of each test method contained in this specification.

1.3 Description of Bondline Performance - It is recognized that structural wood adhesives are used in various applications and under various levels of severity in terms of moisture content, loading, cyclic and seasonal weather conditions, heat exposure and other use conditions. It is the intent of this standard to determine the suitability of an adhesive for use under various levels of severity and conditions of use in accordance with specific and appropriate test methods and requirements. For use in this standard, structural wood adhesives are separated into two classes described in terms of conditions of use, and severity of environmental exposure including the amount of moisture.

Note 2 - This standard does not contain specific tests outlined for different chemical types of adhesives.

1.3.1 Description of Adhesive Service Class A - This service class is characterized by its limited exposure to the weather, including low moisture content conditions and is sometimes referred to as a Protected Service or Limited Moisture Exposure environment. In this service class, exposure of adhesive bondlines in structural wood products to exterior environment is limited to those such as during transportation, construction and accidental exposure where the material may be subjected to a limited number of cycles of short-term wetting and drying.

1.3.2 Description of Adhesive Service Class B - This service class is described wherein adhesive bondlines in structural wood products are subjected to full and repeated or continuous exposure to the weather including high moisture content conditions. This exposure may include fresh and saltwater marine applications as well as possible ground contact. This service class has traditionally been refereed to as Exterior or Wet Service.