LEARNING WHAT CODES ARE AFFECTING FIRE SAFETY
by MICHAEL J. PFEIFFER, P.E.
|Editor’s note: This feature originally appeared as a column in SHELTER’s sister publication, USGlass. It is reprinted with permission.|
On April 8-19, 2002, the International Code Council® (ICC®) held its code development hearings for the 2002 code development cycle on proposed changes to the 2000 editions of the International Codes® in Pittsburgh. During these hearings, proposals affecting glazing were considered relative to the fire safety and skylight requirements in the 2000 International Building Code® (IBC®). The following is a recap of the 2002 ICC code development hearings relative to key glazing issues, preceded by an overview of the key steps of the code update process.
ICC Background and Processes
The ICC code development process is the mechanism by which the family of International Codes is updated. The 2002 cycle was initiated with the submittal of code changes, due November 15, 2001. Any and all interested parties are afforded the opportunity to submit a proposed revision to the International Codes. The code development hearing is the second phase in the process. This will be followed by the public comment period, currently in process, where anyone can submit a public comment in response to the actions taken by the committee on a given proposal. Public comments are due on July 3, 2002. This is followed by a second hearing at the 2002 Codes Forum—Joint Annual Conference on September 29-October 4, 2002, in Fort Worth, Texas. The final disposition on all code changes will be decided by a vote of the eligible governmental members of the three statutory members of the ICC: Building Officials and Code Administrators International Inc. (BOCA); International Conference of Building Officials (ICBO); and Southern Building Code Congress International (SBCCI) at the conference. The results of the 2002 code development cycle will be compiled with the 2002 accumulative supplement to the International Codes; the 2003 editions of the International Codes will be available in early 2003. Instructions for submitting a public comment and details on the Joint Annual Conference can be found on ICC’s website at www.intlcode.org.
The full text of the code changes listed below (i.e. FS 43-02), as well as the published reasons for the committee’s action, can be downloaded from ICC’s website. These documents are titled the “2002 Code Development Cycle Proposed Changes” and “2002 Report of the Public Hearing,” respectively.
Approved code changes FS 43-02 and FS 56-02 clarify that fire-resistance-rated glazing need not be labeled as a fire-protection-rated glazing product. Fire-resistant-rated glazing (IBC Section 714.3.8) is glazing which is tested in accordance with ASTM E119 as part of a fire-resistance-rated wall assembly and not as an opening protective in accordance with NFPA 257 or NFPA 80. As such, all that is necessary to demonstrate code compliance is documentation that indicates the glazed assembly has been tested to the more restrictive parameters of ASTM E119, no differently than any other fire-resistance-rated wall assembly.
Section 714.2.3 of the IBC requires doors in rated corridors to have a fire protection rating of 20 minutes and glazing material used in sidelites and transoms to be tested in accordance with NFPA 257, including the hose stream test, for a fire protection rating of 45 minutes as part of the wall. Submitted code change FS 48-02 proposed an exception to this requirement to allow a 20-minute test in accordance with NFPA 252 without the hose stream where the sidelites/transoms are of limited size. Specifically, the proposal suggested that sidelites limited to a width of 24 inches on either side of a door and transoms above the sidelites be permitted as an exception to the 45-minute requirement. The committee denied the code change based on the premise that the sidelites should not be tested to the door standards but rather should be tested no differently than other windows within a wall assembly, as is required by the current text.
Nonsymmetrical-fire-protection-rated glazing assemblies, such as those with a coating or film on one side, are not explicitly dealt with in the IBC. Since the wall that they are located in is required to be rated from both sides, common sense would dictate that since the glazed assembly is not symmetrical, there is really no way of knowing if the material on one side of the assembly would adversely affect the rating. Approved code change FS 55-02 introduced a new section in the IBC (Section 714.3.2) to require testing from both sides on such assemblies.
The IBC currently includes general loading parameters for sloped glazing in Section 2404.2, based on dead, wind and snow loads. However, the critical load on a skylight will also depend on the climate in which it is installed. Approved code change S186-02 added provisions to the IBC that are unique to individual skylights. These provisions include a reference to a new standard, North American Fenestration Standard—NAFS 1-00, titled “Voluntary Performance Specification for Windows, Skylights and Glass Doors.” This standard establishes performance requirements for skylights that include air leakage and water infiltration in combination with design loads for wind and snow. These load combinations include skylights acting under positive-design pressures (dead, snow and wind loads acting towards the face of the skylight) and negative pressures (wind loads acting away from the face of the skylight and pulling up on the roof and skylight).
As previously stated, the next step in the ICC code development process allows anyone who disagrees with the committee’s decision on a given code change to submit a “public comment.” This allows individuals the opportunity to identify why he feels the action taken at the code development hearing should be reconsidered at the joint annual conference this fall, and what action he feels should be taken by the eligible voting members of BOCA, ICBO and SBCCI.
Michael J. Pfeiffer, P.E., serves as vice president of codes and standards o the Building Officials Administrators International Inc., which is a statutory member of the International Code Council.
Training Information on Fire-Rated Products
|therma-Tru Doors is working to get the word out about new fire-door ratings and an innovative fire-rated, split-jamb frame.
The company has been conducting training sessions for distributors’ sales forces as well as its own territory managers. These salespeople, in turn, can serve as a resource for dealers and jobbers who have questions about the new ratings.
A key goal of the training is to help those in the industry understand the positive-pressure fire tests that have been incorporated into most U.S. codes.
Standards in Europe and Asia have used positive-pressure tests for many years. The Building Officials and Code Administrators International Inc. (BOCA); International Conference of Building Officials (ICBO); and Southern Building Code Congress International (SBCCI) are working together to create a consistent set of fire codes that will meet global standards. As part of this effort, these bodies have begun to incorporate positive-pressure standards for fire doors and assemblies.
Why the Change to Positive Pressure?
Positive-pressure tests are designed to reflect the actual conditions that occur in a fire more closely. As a result, the fire ratings offer an accurate measure of how long a fire-rated entry will provide protection during an actual fire.
To understand the rationale behind these tests, consider what happens in a typical building fire. During a fire, heat and smoke rise toward the ceiling and air is drawn into the room from near the floor, creating higher (positive) pressure near the top of the room, and lower (negative) pressure near the bottom. The “neutral-pressure plane” is the boundary between the positive area and the negative area.
In the early stages of a fire, this effect helps contain a fire. The relatively low air pressure at the base of the room creates negative pressure relative to the pressure in the corridor or outside space. As a result, air tends to flow into the room, keeping the flames and smoke from spreading.
As the fire continues to burn, however, the pressure increases in the upper part of the room. The high-pressure area pushes farther and farther down into the room. When the neutral-pressure plane drops below the top of the door frame, the situation changes: now the high pressure—the positive pressure—tends to force heat, flames and smoke out of the room, through the gap between the header and the top of the door. This condition allows the fire and smoke to spread, and it increases the intensity of the fire in the room by creating a draft.
New positive-pressure tests focus on the ability of the door assembly to resist these effects, by maintaining a tight seal between the door and the frame for as long as possible.
Originally, fire tests in the United States were conducted so that the neutral-pressure plane was at the top of the door assembly, which meant that the entire door would be at slightly negative pressure during the test.
The latest codes, however, call for positive-pressure tests, creating a condition in which the neutral pressure plane is 40 inches from the floor—about halfway up the door assembly. This standard is much tougher than the original negative pressure standard.
Our fire-rated products, along with many other manufacturers, meet the positive-pressure requirements, ensuring that your installations meet current code requirements. Fire-rated doors meeting positive-pressure testing requirements are identified as such on the label.
Split-Jamb Frame Eases Installation
Our company is also offering training on its fire-rated, split-jamb system.
The frame is manufactured in two halves, with the edge of the closure frame sliding into a channel on the base frame. This construction allows the width of the frame to be adjusted up to one-half of an inch during installation. The adjustability makes the frame especially useful for renovation work where wall thicknesses may vary. The frame is also ideal for new construction, with wood stud, metal stud and masonry openings.
The split-jamb design allows the frame to be installed quickly and easily, even during a retrofit. Typically, the entire door and frame can be installed in 15 to 20 minutes on the jobsite.
The frame can be shipped preassembled, with the door prehung, ensuring that the door fits precisely into the frame and proper margins are maintained between the door and the frame.
As fire door requirements change and products evolve, we will continue to work to keep distributors, dealers and installers up-to-date.
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