Is a hose stream test required for top-of-wall and wall-to-wall joints under ASTM E1966-UL0079?

The requirement for a hose stream test in relation to top-of-wall and wall-to-wall joints under ASTM E1966-UL0079 is based on the need to evaluate the structural integrity and performance of these joints in the presence of fire conditions. This standard focuses on the fire resistance of wall assemblies and includes testing that simulates conditions that could occur during a fire.

The correct choice, indicating that the hose stream test is required specifically for top-of-wall and wall-to-wall joints, recognizes the critical role these joints play in maintaining the overall performance of fire-rated wall assemblies. The hose stream test assesses the joints' ability to withstand not only the thermal impacts of a fire but also the physical stress that occurs when water is applied to cool down the structure, simulating firefighting efforts. This testing ensures that the materials and construction types used are capable of performing under these conditions, which is essential for fire safety.

While the other options propose different scopes for the requirement, they do not capture the specific need for testing on the types of joints indicated in the correct answer. Therefore, the emphasis on these particular joints within the standard signifies their importance in the overall fire resistance of structures.