What is the term for a joint that is designed and tested to allow movement in a firestop system?

A joint designed and tested to allow movement in a firestop system is referred to as a dynamic joint. This term is crucial because dynamic joints are specifically engineered to accommodate the expansion and contraction that can occur in building structures due to factors like thermal changes or seismic activity.

Dynamic joints maintain the integrity of the fire-rated assembly while permitting movement, which is essential for preventing the spread of smoke and fire during a fire event. Firestop systems must effectively balance the need for flexibility with the requirement to contain flames and smoke within a compartment.

In contrast, static joints are designed to remain rigid and do not allow for movement, while fixed joints are typically used in scenarios where no movement is anticipated. End joints refer to connections at the terminus of a firestop assembly and do not specifically address the movement aspect essential for maintaining firestop functionality.