A building joint is a junction where

building A building or edifice is an enclosed Structure#Load-bearing, structure with a roof, walls and window, windows, usually standing permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, a ...

elements meet without applying a static load from one element to another. When one or more of these vertical or horizontal elements that meet are required by the local building code to have a fire-resistance rating, the resulting opening that makes up the joint must be firestopped in order to restore the required compartmentalisation.

Qualification requirements

Such joints are often subject to movement. Firestops must be able to demonstrate the ability to withstand operational movement prior to fire testing. Firestops for such building joints can be qualified t
UL 2079 -- Tests for Fire Resistance of Building Joint Systems
The joint design must consider the anticipated operational movement of each joint. Timing is also important, as freshly poured concrete shrinks particularly during the first few months of a new building, potentially causing joint size changes.

Head-of-Wall (HOW)

Where vertical fire-resistance rated wall assemblies meet the underside of the floor slab above, a movement joint results, which can be subject to compression, as the freshly placed concrete cures and shrinks all over a new building. This joint must be firestopped in a flexible manner.

References

External links

{{Commons category, Building joints, Building Joints
UL2079 Scope: Tests for Fire Resistance of Building Joint SystemsUL treatise on building joints
Building engineering Passive fire protection Firestops

Qualification requirements

Head-of-Wall (HOW)

See also

References

External links