What role does expansion play in the functionality of firestop products?

Expansion plays a critical role in the functionality of firestop products, particularly when it comes to their ability to maintain the integrity of fire-resistive assemblies during a fire. When exposed to high temperatures, many firestop materials, such as intumescent sealants, expand significantly. This expansion helps to fill gaps and openings that may occur as materials in the structure begin to degrade and shift due to heat.

As materials experience thermal expansion, they can shrink or pull away from the structures they are meant to protect, potentially creating openings that allow fire or smoke to pass through. The expansion properties of firestop products ensure that these gaps are effectively sealed, thus preventing the spread of fire and smoke throughout different areas of a building. This function is essential for maintaining the safety and integrity of fire-rated walls, floors, and ceilings, enabling the firestop products to fulfill their intended protective roles during a fire event.