Firestopping devices are forms of passive fire protection used to seal the openings or passages in fireproof floors, walls, or ceilings and to impede the spread of flames, smoke and toxic gases. A firestop device fills the holes created during the installation of communication or electricity cables, plumbing, or ventilation ducts. It contains a soft fire-retardant material (usually red) that closes the gaps between pipes, cables, ducts, holes, edges, etc.– thus blocking fire and smoke from spreading and enhancing safety for building occupants. Firestopping is currently required for top of walls, curtain walls, slab edges, joints, and pipe penetrations. Note that firestopping should not confused with fireproofing which is the spray-on product applied to building materials.
According to the Preformed Firestop Devices Market 2022 Report the global preformed firestop devices market appreciated to $284 million in 2020 and is predicted to reach $522.2 million by 2030.
Types of Firestop Systems
There are four system types:
- Through Penetrations – consist of a fire-rated wall or floor, a penetrating item (pipe, cable or duct) and the firestop material
- Membrane Penetrations – protect penetrations that pass through a part of the barrier, but not the whole barrier, like sink drains or outlet boxes
- Fire Resistive Construction Joints – protect the joints or spaces installed within or between fire-rated assemblies, like where the wall meets the deck of the floor above
- Perimeter Joints – separate the tile covering from enclosure or partition structural elements and require firestopping the edge of the slab along the perimeter of the building
The Need for Firestopping
During the MGM Grand Hotel and Casino fire that occurred on November 21, 1980 in Las Vegas, a total of 85 people were killed. While the fire only damaged the second floor, the smoke and toxic gases spread through the building – resulting in 61 deaths on the 19th to 24th floors of the hotel, with one young couple dying in their sleep. Since most of the deaths occurred through smoke inhalation in the hotel’s upper rooms, the tragedy galvanized the discussion about appropriate firestopping in the construction industry and the use of intumescent (swell up when heated) materials precisely intended to stop the spread of fire, smoke and gasses.
The firestopping passive protection helps assure building occupants that there is enough time to exit the building before fire, smoke and gases spread throughout the building – even if the active systems, such as sprinklers, fail.
Firestopping Design and Requirements
Firestopping is specifically engineered to confine a fire to the zone of origin, for a specified period indicated by the number of hours. For example, a two-hour F (flame) rating means that the firestop system will prevent fire spread for two hours before being consumed and permitting the passage of the flame through the opening. A T (thermal) rating is the number of hours that the temperature on the non-fire side of the wall does not exceed 325 °F or 163 °C above the ambient temperature – ensuring that the temperature does not reach the flash point of any materials on that side of the wall. The L (leakage) rating is the amount of cold smoke that can leak through the penetration in cubic feet per minute.
The firestopping is generally made from cement-based or intumescent products, putties, noncombustible fibers, and rubber compounds. Firestopping systems are tested and approved for use by nationally-recognized testing laboratories such as Underwriters Laboratories, Intertek Testing Services, or Omega Laboratory.
The 8.3.4.2.1 Firestop Systems and Devices Required section of the International Building Code (IBC) states that: “Penetrations for cables, cable trays, conduits, pipes, tubes, combustion vents and exhaust vents, wires, and similar items to accommodate electrical, mechanical, plumbing, and communications systems that pass through a wall, floor, or floor/ceiling assembly constructed as a fire barrier shall be protected by a firestop system or device.” Also, the Life Safety Code (NFPA 101), National Electrical Code (NFPA 70), NFPA 5000 (NFPA Building Code), and Legacy U.S. building codes (UBC, SBC, NBC) require the use of firestopping.
Firestopping Assessment
The firestopping assessment process is labor-intensive and takes time to detect unsealed penetrations. For example, a 50-unit housing complex may have more than 20 inspection areas per unit encompassing plumbing pipe, drain, cable, electrical conduit and joints – resulting in more than 1,000 items that must be listed, assessed, and rectified if necessary. Both the ASTM E2174 Standard Practice for On-Site Inspection of Installed Firestop Systems and ASTM E2393 Standard Practice for On-Site Inspection of Installed Fire Resistive Joint Systems and Perimeter Fire Barriers state that “an inspection form shall be written and clearly describe the results of the inspection and any deficiencies.”
The 2012 International Building Code requires third-party, special inspections of firestopping for buildings over 75 feet in height and category III and IV buildings (IBC article 1705.16) – by either witnessing installation of systems or performing post-installation destructive inspection on already installed systems. Per ASTM Standards, the firestop inspector has to witness 10% of installations or perform destructive testing on 2% of installations for wall penetrations. Similarly, for fire resistive joint systems, the inspector has to be onsite during installation and randomly witness a minimum of 10% of each type of firestop being installed. Alternatively, the inspector must conduct a post-installation inspection, which requires destructive-type verification of the firestop and repair of the firestop. It also should be noted that “the local authority having jurisdiction must approve firestop system details and firestop products.”
Firestop Services…from HETI
HETI staff can help our clients meet these inspection requirements. In addition, we can apply our knowledge and expertise to professionally assess firestop verification/repair and code compliance, as required to meet regulatory standards.
Remember that the goal of firestopping is the life safety of building occupants and protection of property!