Firestop System Application Clarification

Through Floor Penetrations of Non-Rated Floor/Ceiling Slabs

A commonly asked question is whether or not penetrations of floor slabs, floor/ceiling assemblies, and roof/ceiling assemblies that are otherwise not required to be fire resistance rated, require protection by an approved through-penetration firestop system to maintain the integrity of the floor slab. In accordance with 780 CMR 714.5, the protection of such penetrations is dependent on the type of penetrant and the number of stories penetrated as outlined below:

1. All combustible penetrating items connecting more than two-stories and all noncombustible penetrating items connecting more than five-stories are required to be protected within a shaft in accordance with 780 CMR 713.

2. For all penetrating items connecting not more than two stories, the annular space of the penetrating item is required to be fireblocked in accordance with 780 CMR 718.2.5 to resist the free passage of flame and products of combustion (780 CMR 714.5.2). Such materials include batts or blankets of mineral wool or mineral fiber installed such as to be securely retained in place or cellulose insulation installed as tested for the specific application without requiring the application to be a listed firestopping assembly (780 CMR 718.2.1).

3. For all noncombustible penetrating items connecting not more than five-stories, the annular space of the penetrating item is required to be fireblocked in accordance with 780 CMR 718.2.5 to resist the free passage of flame and products of combustion or be filled with a fill, void, or cavity material that is tested and classified for use in a through-penetration firestop system (780 CMR 714.5.1). As such, these penetrations may either be protected as outlined by Item 2 above or the annular space may be filled with a listed product such as intumescent firestopping without requiring the application to be a listed firestopping assembly.

Continue to monitor the Code Red Consultants Blog for code updates and search “Firestop” for more information on firestopping assemblies are when Third Party Firestopping Special Inspections are required.