The Firestop Industry...

by Bill McHugh, Jr.  

Copyright, William J. McHugh, Jr. January, 1998, all rights reserved.

History of Industry - Disaster spawns the Firestop Systems Industry 

The need for Firestop Systems became apparent after the Browns Ferry Nuclear Plant fire in Alabama. Urethane Foam was used as a "Firestop Material" in electrical conduit pipe penetrations through fire rated walls and floors. Fire started when a worker, trying to test the material for smoke containment, held a candle under the fire/air seal. When the "seal" ignited and burned, fire spread rapidly affecting critical power station control systems. An untested, unlisted material not meant for use as a "Firestop System" caused a disaster. Other major fires around the country where lack of or improper use of "Firestop Systems" caused damage include:

  • First Interstate Bank - Los Angeles - 1988 - $50,000,000 loss and 30 injuries in a late evening fire. Sprinkler system inoperable due to maintenance.

  • Meridian Plaza - Philadelphia - 1991 - Multi Billion lawsuit, 3 deaths. Sprinkler system inoperable due to electrical failure at controls.

  • MGM Grand Hotel - Las Vegas - 1980 - 85 deaths. Joints, shafts allowed smoke to pass quickly to upper floors.

Based on disasters like these, National Code Organizations BOCA, ICBO, SBCCI and NFPA added provisions to their model codes that Tested and Listed Firestop Systems meeting the requirements of ASTM E-814 be installed in penetrations of walls, floors, gaps and joints. These Firestop Systems prevent the fast spread of fire between compartments reducing property damage and saving lives. This is especially important where people are confined inside a large building without easy exit access, immobile or attached to life support systems.
Architects & Engineers, Departments of Public Health, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), Building Owners, building and fire officials began stiffening Firestop System requirements. And, field inspectors from each organization started taking notice of "holes in firewalls/floors "requiring Firestop Systems with community life safety in mind.

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  Definitions - What are Firestop Systems?

Firestop Systems were developed to produce a "Compartmented Space" where fire from outside the compartment will not enter the protected area. Tested and listed fire walls and floor assemblies surround the compartment. All penetrations, gaps and joints in the assembly are sealed with tested and listed "Firestop Systems" to maintain the integrity of the rated wall or floor system.

Firestop Systems are combinations of products assembled in the field or premanufactured that, once installed correctly to a U.L. rated design, prevent the passage of fire, air and temperature between compartments. All Firestop Systems are tested under the same ASTM standard to ensure repeatablity and "suitability for use" in the specific application. The largest facility for testing Firestop Systems is at Underwriters Laboratories Northbrook, IL Fire Testing Laboratory. Other labs including Omega Point, Factory Mutual and Southwest Research test "Firestop Systems" as well.

ASTM E-814 is the standard for testing Firestop Systems Performance. Listed below are the ratings that result from ASTM E-814 Test Method:
  • "F" Rating - Fire Rating, in hours; time for the fire to "poke through" the Firestop System to the non-fire side of the test assembly.

  • - "T" Rating - Time for penetrating item (pipe, duct, etc.) to raise 325F above ambient. Flammable materials on the "cold side" of the penetration can ignite without flame passing through the opening.

  • Conductive transfer of a heated copper or metal pipe to cardboard or plastics and other flammable on the "cold side" can cause fire spread without flame penetrating the opening.

  • - "L" Rating - Air leakage of the firestop system at ambient and 400F, simulates cold and hot smoke, stated in CFM/SF opening area. This is the industry’s solution to "smoke wall" sealing.

  • - UL 2079 - "F", "T", "L" Ratings, tested after cycling joints and gaps of wall tops and expansion joints, (some 500 times plus) then fire testing the system when the joint is at extension to simulate the worst case conditions. This rating is stated in hours as well. Another hybrid of the test is CWS - 2001, a system for testing gaps at floor slab edge/curtain wall assembly junctures.

Firestop Systems tested to these ASTM E-814 criteria must be assembled as tested before a rated system can exist. The concrete wall/floor must be tested and rated, the caulk and wrap strips must be installed as tested, pipes and insulation types installed as described as well. Any variance in the field nullifies the system making the assembly only "a hole in a fire wall/floor filled with something that may not perform in a fire."

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Products that make Firestop Systems

Different types of metals react in various ways when subjected to fire. Plastics and insulation may completely melt away in a short time. Fiber optic cabling in protective inner duct tubing melts faster than traditional copper cables leaving large openings where fire can penetrate a compartment. The "orange plastic" inner duct conduit disappears quickly in a fire. Construction joints and wall top gaps offer large risks to a building as fire can spread unchecked above hanging ceilings leaving expensive fire walls useless.

Because building materials for walls and floors and the penetrating pipes/gaps react differently in a fire situation, only a "Firestop System" that has been tested and listed in the exact application that exists in the field should be used. Fire can travel through openings not treated with firestop systems quickly. Firestop Systems prevent the fast spread of fire through walls and floors. Any variation from the tested system may not perform in a fire condition posing a life safety risk to the building occupants.

To combat the spread of fire, "Firestop Systems" Products have been developed to be used in a tested "Firestop System". These products are of many types. "Intumescent" sealants, wrap strips and sealbags, expand when exposed to heat filling a void created when plastics and insulation melt. Silicone and Latex Sealant Firestop Systems are used around metal piping, joints and gaps. Firestop Mortar materials, either portland cement or gypsum based are used for large and small openings. Specialized stainless steel frames with intumescent inserts and composite sheet Firestop Systems have been used for cable applications in high tech environments. Prefabricated plastic pipe devices and plastic piping assemblies have been used throughout the U.S. in various applications. These materials have all been tested and listed .

 

Summary

The overall objective of "Firestop Systems" is to save lives, protect property and provide continuity of operations for building owners if a fire occurs in their building. The return on investment can be dramatic for businesses through lost time minimization. Business interruption insurance is meant to cover the business owners losses. However, insurance can’t cover the loss of business momentum lost due to shut down operations.

"Firestop Systems" is a total system oriented program in construction with a specific protocol for installing listed and Tested Systems. Fire walls/ floors, Firestop Systems, Fire Damper Duct Assemblies, Fire Doors and Fire Rated Glass all work together to contain/compartment fires to the point of origin. Together with active fire protection systems (sprinklers, alarms), a total life safety system is accomplished.

The firestop system is the fire wall, the penetrating item or gap, mineral wool at a certain depth, caulk at a specified thickness or other material combinations required by the tested assembly. Each combination of products used in a firestop system is engineered to perform a specific function during both its "in service life" and "actual fire use".

Remember, THERE IS NO SUCH THING AS A CAULK THAT MAKES A NON FIRE WALL INTO A FIRE WALL....OR A "2 HOUR CAULK". Protect property, keep businesses operating through minimal downtime if a fire occurs and, most importantly, save lives through the use of a tested and listed firestop system installed by a specialty firestop contractor.