The combination of stress and moisture decreases the durability of most adhesive joints. Stresses in the presence of water or water vapor may cause some adhesive joints to fail at some small fraction of the stress required to break the dry joint. The time to failure for a given adhesive joint generally decreases with increasing stress, temperature, and relative humidity.

This test method may be used as an accelerated screening test for assessing the durability of adhesive joints. It may be used to measure durability of adhesive joints exposed outdoors or to environmental conditions experienced by adhesive joints in service. It may also be used to determine the effects of various surface preparations or substrates on durabilities of adhesive joints.

The durability performance of various adhesives may be compared by using this test method under uniform sets of conditions. To assess the overall durability of a given adhesive, T-peel joints should be tested under a range of stress, relative humidity, and temperature. For a specific end use it may be possible to obtain the needed durability data using only one set of test conditions.