Firestopping Is the Designer's Responsibility
The United States continues to have one of the worst fire records in the industrialized world in both commercial and residential structures. The price of fire loss reaches the billions, not including the cost of injuries, losses from businesses that must close, and from jobs that are interrupted or lost. This is in spite of the fact that researchers, scientists and design professionals have addressed fire protection principles for nearly three centuries in this country.
The first American building code, proclaimed in 1631 by Governor Winthrop of Plymouth, contained restrictions that were
intended to limit the spread of fire from building to building within the settlement. Today, building codes contain stringent and
specific requirements that are intended to ensure building occupants protection from fire. Yet, these requirements, which are
based on well-accepted fire protection principles, are often reluctantly or only superficially complied with, traded-off or simply
ignored. Post-fire investigative reports show this inattentiveness can lead to disastrous results. It's worth examining some essential
prevention methods to remind us how designers and engineers make a significant difference in fire prevention.
CompartmentationThe most well-established of all fire protection principles is compartmentation. Compartmentation is the method of construction that attempts to limit or contain the spread of fire to its area of origin through the construction of barriers, such as fire resistive floors, floor/ceiling or roof/ceiling assemblies, and walls. Compartmentation is the basis of nearly all commercial building design in the country today. Compartmentation also encompasses secondary features in fire resistive construction such as fire doors, penetration seals, joint systems, fire dampers and similar passive construction elements that maintain fire resistivity and continuity of the floor, ceiling and roof, and wall assemblies.
Fire resistive construction is most often compromised by two simple mistakes. First, fire doors are often tied or propped open, allowing fire, toxic gases and smoke to travel unimpeded through corridors and into stairways used for egress. And second, penetrations that are made in fire-rated walls and floors-to accommodate all types of piping systems, electrical, HVAC, telecommunications and similar building services-are often left unprotected or improperly protected. Such negligence permits fire, toxic gases and smoke to travel throughout the building, contaminating many remote areas that would otherwise be unaffected by a fire.
In order to monitor the condition of fire doors, among other things, fire inspectors or fire marshals make routine unannounced
inspections. Because of countless tragedies attributed to unprotected or improperly protected penetrations, many building
departments require that piping and mechanical engineers provide the methods and materials that should be used to protect their
materials when they penetrate fire resistance rated construction. Model building codes, on which most local codes are based,
require that the construction documents include documentation or supporting data substantiating all required fire resistance
ratings, including details and material for providing the required fire resistance rating at penetrations of piping and other material.1
It is imperative that the designer be aware of how the systems they are designing affect the fire resistance rating of the assemblies
penetrated. The building codes refer to the discipline of protecting penetrations and maintaining the fire resistance ratings as
Firestopping Through-PenetrationsThe standard test method for firestopping through-penetrations is ASTM E-814 or ANSI/UL 1479. In CSI and Masterspec specifications written since 1996, general information on firestopping is located in Section 07840. Prior to that, firestopping was located in Section 07270. Other sections such as Insulation, Mechanical and Plumbing may contain specific information on firestopping.
There are several independent laboratories that conduct the tests to evaluate firestopping methods and materials, including Underwriters Laboratories, Omega Point, Warnock Hersey, Southwest Research Institute and Factory Mutual. They publish directories to assist a designer in selecting the most appropriate firestop systems for specific types of piping or mechanical systems.
The laboratory that offers the greatest number of tested firestop systems is Underwriters Laboratories. The 1998 UL Fire Resistance Directory Vol. 2, page 100, offers an explanation of their alpha-numeric locator system.2
In a nutshell, the tested firestop system is given a letter designation indicating what type of floor or wall assembly the firestop system has been tested in: concrete, masonry, gypsum, etc. Following the letter is a number designation referring to the type of penetrating item that has been tested, such as metallic pipe, non-metallic pipe, cable, electrical, etc.
For example, System # CAJ-1044 is deciphered as follows:
- C = Either floor or wall
A or J = Concrete floor or wall, with minimum thickness less than or equal to 5 or 8 inches, respectively.
1000 to 1999 = Specific types of metallic piping and specific diameters.
#1044 is the 44th system in the 1000 series of metallic penetrations.
The system can be used in reverse, selecting the type of piping first by determining the number range (1000 to 1999 is metallic pipe; 2000 to 2999 is non-metallic pipe, etc.), and then reviewing those systems to find the type of assembly penetrated (a framed wall or floor, concrete or masonry floor or wall, etc.).
Also located in the UL Fire Resistance Directory Vol. 2 are the F, T and L ratings for each firestop system, hourly ratings that indicate specific performance capabilities and correspond to building code requirements. The Directory defines these ratings as follows:3
The F rating provides "the time period for which the system is capable of prohibiting the passage of flame through the system and requires acceptable hose stream performance."
The T rating provides "the time period for which the system is capable of limiting the maximum temperature rise on the unexposed surfaced of the wall or floor assembly, on the penetrating item, and on the fill material in the annular space, not to exceed 325° F (181° C) above ambient teperature, and requires acceptable hose stream performance."
The L rating provides "information concerning the amount of air leakage, in cubic feet per minute per square foot of opening through the firestop system and/or 400° F air temperatures at an air pressure differential of 0.30 in W.C."
his information is vital to the designer. If the wall assembly is rated for two hours, the building codes require that the F rating of
the firestop system must be equal to that of the assembly penetrated. In other words, the firestop system must have a two-hour F
rating in order to be specified for a two-hour wall assembly. In some cases, the building code requires that the T rating must be
equal to that of the floor assembly penetrated. In other words, the firestop assembly must have a two-hour T rating in order to be
specified for a two-hour floor assembly. There are no requirements pertaining to the L rating in any building code at this time,
although the information may be useful to a designer when the design includes miscellaneous openings in floors and penetrations
in smoke barriers in accordance with the National Fire Protection Association Life Safety Code, NFPA 101.
Practical ConsiderationsOnce the correct system has been specified, it becomes the contractor's responsibility to provide documentation to the building department that the installations were made correctly, in accordance with the manufacturer's and the laboratory's listing. In nearly all cases where firestopping was a problem on the job site, it can be traced back to improper or insufficient specification of methods and materials. Costs are greatly reduced when firestopping is addressed early in the job, including pre-construction meetings.
For these reasons, it is becoming more common for building departments to reject plans without sufficient firestopping specs and details, sending them back to the designer with the firestopping deficiency noted.
Unfortunately for the educated mind, the simple task of filling an opening containing a single metal pipe with a caulking
material to a specified depth is painfully uncomplicated. Yet it is the simplicity of the task that causes so many to approach the
firestopping issue casually. During building department inspections, all kinds of inappropriate materials have been excavated from
through-penetrations, including wadded-up paper covered with dry wall compound, flammable urethane foam, corrosive
cemetitious mixtures and other mystery materials. Contractors inevitably try to save money by cutting corners, sometimes
inappropriately. But that should not correspond to the failure of the designer to provide specific direction on how to properly
maintain the fire ratings, and also to specify the proper firestopping materials that will not damage the piping or mechanical
The Prevention ConnectionUnlike other disasters, the injuries, death and property destruction caused by fire are preventable, or at least manageable. That presumption is, however, based on making correct, proactive decisions. Fire protection is everyone's responsibility, beginning with the designer and ending with the occupants of the building. Through improved awareness and an ongoing willingness to be educated on specific fire issues, we can create environments where fire is one disaster that we may rarely have to face.
Information is available to designers on how to specify firestopping materials from the members of the International Firestop
Council. A directory of the manufacturer members may be obtained by mailing a request to Rich Byrne, Executive Director, IFC 25
N. Broadway, Tarrytown, NY 10591.
Endnotes1 1996 BOCA National Building Code, Section 703.0 Construction Documents, 703.1 General, Building Officials and Code Administrators International, Inc. 4051 Flossmoor Road, Country Club Hills, IL 60478-5795
1997 ICBO Uniform Building Code, Section 106 Permits, 106.3.3 Information on Plans and Specifications, International Conference of Building Officials, 5360 Workman Mill Road, Whittier, CA 90601-2298.
1997 SBCCI Standard Building Code, Section 104 Permits, 104.2.4 Structural and fire resistance integrity, Southern Building Code Congress, International, Inc. 900 Montclair Road, Birmingham, AL 35213-1206
2 and 3 Fire Resistance Directory Vol. 2, 1998, Underwriters Laboratories, Inc. 333 Pfingsten Road, Northbrook, IL 60062-2096