"Active" fire suppression includes mechanical systems that are designed to control and/or extinguish fires after they have been started, such as sprinklers. These fire safety devices are readily apparent in most buildings and require maintenance and inspection on a regular basis. But, active systems can have a high rate of failure and do not guarantee stopping or suppressing the spread of deadly toxins, smoke and flames.
"Passive" fire protection or "firestopping," is an integral part of fire protection engineering. Firestop systems protect against the passage of flames, deadly gases and toxic smoke through openings in walls, floors and floor/ceiling assemblies for through-penetrations, membrane penetrations, joints, blanks, gaps and voids. The integrity of fire-rated assemblies is restored by firestop systems. Other materials, such as duct enclosures, mineral wool insulation, and fire-rated drywall, are also critical in forming fire-resistive compartments in buildings. Passive fire-rated systems are installed during construction to ensure in the event of a fire that the flames, smoke and deadly gases can be contained within the area that the fire started.
Firestopping is required in all penetrated rated assemblies and the joints. All of the model building code groups (BOCA, ICBO, SBCCI, ICC) follow a common format for specifying firestopping. NFPA also specifies firestopping requirements in its Life Safety Code, National Electric Code publications and NFPA 5000 Building Code. In fact, the very nature of the NFPA promotes the use of a "belt-and-suspenders" approach to ensure proper firestopping rather than an "either/or" approach.
Passive fire protection is required to be a fire rated system tested at an independent laboratory, such as UL, FM, Omega Point and/or Warnock Hersey. In other words, manufacturers sell products that are used in total systems based on a number of building components and configurations. "Systems" are firestopping techniques or methods, tested by an independent laboratory to ASTM or Canadian test methods, using a firestop product or combination of products to determine the fire-rating performance. When installed, selected, inspected and tested properly, these products work in concert with one another to create effective barriers.
Choose the right passive fire protection systemDepending on the application, there can be many firestopping product and system choices. As a rule of thumb, firestopping is required at all joints and penetrations that run through fire-rated walls. There are other areas, such as grease or air duct systems, that might require further firestopping, as well.
The first step in selecting a firestopping system is to identify items penetrating the fire-rated assembly, such as cables or pipes, or the type of joint, static or dynamic. Use the following guidelines to determine the correct firestopping system to meet the project's needs.
Through penetration guidelines:
• Type of assembly (concrete, gypsum wallboard)
• Type of penetrant (Metallic pipe, non-metallic pipe, cables)
• Size of opening
• Size of penetrant (diameter)
• Rating required
• Width of joint
• Type of assembly (concrete, gypsum wallboard)
• Rating required
If unable to find a specific system that fits the application, an engineering judgment can be written to fit the particular firestop need. Beyond the standard, listed firestop systems, engineering judgments can help properly address unanticipated construction configurations. Most (if not all) manufacturers follow International Firestop Council guidelines on engineering judgments and offer this service free of charge to the benefit of the industry. An engineering judgment must be approved by the architect or inspector responsible for the project.
Proper firestop engineering judgments should:
• Follow the IFC guidelines on engineering judgments.
• Be presented in appropriately descriptive written form with or without detail drawings (as necessary).
• Clearly indicate that the recommended firestop system is an engineering judgment and not a listed system.
• Identify the job name, location and firm the engineering judgment is issued for, along with the nonstandard conditions and hourly rating required.
• Provide complete descriptions of critical elements for the firestop system configuration.
• Include clear directions for the installation of the recommended firestop system.
• Include dates of issue and authorization signature, as well as the issuer's contact information.
• Reference tested system(s) on which the design is based upon.
• And, justification (such as UL, OPL or other independent laboratory system(s) and/or opinions).
It's important to note that an engineering judgment is not a substitute for a tested system, and an available tested system should always take precedent over a judgment. Judgments are most often used in construction configurations that are not standard.
InstallationFirestop is not a separately licensed construction trade, so many different trades install their own firestop. It is common to find electricians, plumbers or drywallers who may install firestopping systems. While this is perfectly acceptable, some trades will subcontract to firestopping contractors.
In fact, because of the codes and inspectors increased knowledge of firestopping, Factory Mutual Research, has developed a standard (FM 4991) in conjunction with the Firestop Contractors International Association, for approval of contractors, to help improve the performance and installation of firestop systems.
To become approved, the contractor firm appoints a Designated Responsible Individual, who must past a rigorous industry test to become the key person in the firm to monitor the quality process. FM Approvals then audits the contracting firm's procedures in its "Quality Manual" to confirm that the firm's paper trail is in order for successful installation of firestop systems.
However, FM 4991 is currently not required of installers to install firestopping systems. It is expected to become a requirement in the future as firestopping awareness increases. Many manufacturers offer training to installers on how to properly read and install systems. This training and some basic understanding of the importance of following a system for proper installation makes firestopping easy for trades, such as drywall, electrical and plumbing.
The inspection processAs with all construction, inspections are necessary. Planning and communication between the building designer and installer prior to construction will save time, money and resources. With firestopping, the time allocated for inspections can be drastically reduced if proper paperwork is present in advance of the field inspection. This paperwork includes copies of all the systems, product data information and MSDS of all products used on the project.
Verification of system testing and listing with a nationally recognized laboratory is key to a smooth inspection process. The costs and time associated with removing improperly applied materials can be drastically reduced if the respective through penetration firestop systems, fire-resistive joint systems and flexible rated duct enclosure documentation are confirmed prior to installation. Use of applicable ASTM practices will provide guidelines for inspection of installed systems.
Firestopping is an important part of an overall fire safety system. The responsibility for firestopping is a shared one-with proper coordination between general contractors, subcontractors, building owners, inspectors, and manufacturers, installing a firestopping system can be a seamless, cost effective mode of enhancing life safety and building longevity.