What function does a firestop serve in fireproofing?

A firestop serves a critical function in fireproofing by sealing openings and maintaining fire-resistance ratings. This is essential for preserving the integrity of fire-rated walls, floors, and ceilings. When a fire occurs, it can generate heat and smoke that travels through openings such as pipes, cables, or ducts that penetrate fire-rated assemblies. Firestops are specifically designed materials that fill these openings, thereby preventing the spread of fire and smoke, and maintaining the intended fire-resistance of the construction elements involved.

By effectively blocking these pathways, firestops help to compartmentalize a building and allow for specific areas to remain safe for a longer period during a fire event. This can provide critical time for evacuation and firefighting efforts. Furthermore, using firestopping systems correctly can ensure compliance with building codes and safety regulations, which specify necessary fire-resistance ratings in various components of a structure.

Other options, although relevant in some contexts, do not accurately describe the primary function of firestops. Firestops do not detect fires, reduce costs directly, or serve merely as decorative barriers; rather, their main role is to provide essential fire protection through effective sealing methods to preserve structural integrity and safety during a fire.