What is the role of mechanical pressure in a mechanical firestop system?

Mechanical pressure plays a critical role in a mechanical firestop system by ensuring that the components are securely held in place to create an effective seal. This is vital in maintaining the integrity of fire-rated assemblies since any gaps or misalignments could allow smoke and flames to pass through during a fire event.

Firestop systems are designed to prevent the spread of fire and smoke between different compartments within a building. By using mechanical pressure, these systems can effectively compress sealants, intumescent materials, or other firestop components against the surfaces of building materials. This compression enhances the performance of the firestop by optimizing the contact between the materials, thereby improving the overall seal against fire and smoke penetration.

While the other options mention various actions or roles, they do not accurately reflect the function of mechanical pressure in this context. Igniting components would be counterproductive in a firestop system, as would cooling surrounding materials or expanding the structure of a barrier, as these do not contribute to the primary goal of creating a secure seal to prevent the passage of fire.