What is primarily the function of Head-of-Wall joints?

The primary function of Head-of-Wall joints is to allow for wall height expansion and contraction. This is essential in building construction because materials such as concrete, masonry, and metal can expand and contract due to changes in temperature and humidity. If these movements are not accommodated properly, it can lead to cracking, misalignment, or structural damage over time.

Head-of-Wall joints are specifically designed to accommodate these movements at the top of interior walls, allowing the walls to flex without compromising the integrity of the overall structure or causing damage to the adjoining elements. This flexibility is crucial in maintaining both the functionality and durability of the building, particularly in areas prone to significant temperature variations or seismic activity.

In contrast, connecting different flooring materials, facilitating structural support, or providing stopping points for vertical surfaces do not capture the primary purpose of Head-of-Wall joints, which centers around the need for accommodating expansion and contraction specific to wall height.