ALA Article on Fire Protection

Optimization of Fire protection Systems

Great use of resources or public safety risk? A few ideas offered to the design professional by William J McHugh 
 

The construction industry is a fascinating place to spend a career. The wide variety of projects, new and retrofits, always tap your talents to their maximum. An architect friend once said to me, "A construction project is like General Motors coming to your front yard, dropping parts (and hiring labor that may never have worked together) and building a car on location instead of at the factory. How the building comes together and works at occupancy time is a great feat of human cooperation".

In the last 20 years, our economy has become much more global than ever. Competition in each industry, automotive, computers, electronics and component parts has driven firms to "get competitive or die". Construction is no different. Firms are now searching the world for places to build manufacturing, warehousing and headquarters facilities, instead of "just a few US states. Economists call this "optimization of resources". This "economic optimization process" has made the passion to be the best and most economical a key focus of excellent firms worldwide.

"Economic optimization" has had a profound effect on firms' decision making behavior. The concept has had successes and some stumbling blocks to deal with along the way. Some firms "over optimized" economy causing failures. Remember the Ford Pinto gas tanks in the 70's, Corvair's rear end configuration problems in the 60's, general auto quality in the early 80's....and the resulting losses of life, safety and profits? "Over epitomizing" can be a disaster. Under epitomizing can mean products that are not competitively priced in world markets.

There has to be a balance somewhere between optimization for competitive reasons and safety. In the automotive industry, end users respond quickly to "rotten construction" at the dealer's service departments. Data is gathered on each vehicle to find sub par performing parts. Then, a "search and destroy" mission is launched to find and repair the problem.

In the construction and fire protection industries, feedback mechanisms aren't that quick. Cars are driven daily, Fire Protection Systems are not. Do we really want to expose people to fire and smoke risks to find out that an "optimization program" didn't work in an actual fire condition? The intelligent person thinks not! Listed below are a few optimizations that have taken place over the years, some very successfully:

  • Concrete Block construction to Plaster, then 1 or 2 layers of Drywall for fire resistance rated wall assembles.
  • Multi ply built up to single ply membrane roofs...with trends pointing back to multi ply built up systems.
  • Using fire resistance rated drywall assemblies and "a bead of firestop caulk" around 4" PVC drain, waste or vent pipe penetrations through fire resistance rated floor assemblies in timber frame construction eliminates the need for "intumescent collar" firestop systems in floor applications.
  • Reducing thicknesses of Sealant/Spray so there's little "margin for error" in firestop perimeter gaps, expansion joints and piping.
  • Using firestop contractors inexperienced in the "Protocol" required to handle a "life safety" application.
  • Adding sprinklers to buildings can eliminate use of fire resistance rated wall assemblies and compartmentation.

For many of these "optimized systems", each component's performance is critical to the safety of the other component and the structure. If one part of a system has a weakness, complete failure can be the result. In fact, the "Margin for Error", or safety factor, may not exist when the "optimization process" is used. Everything has to work without flaw for the system to be functional. And, remember, in the construction industry the "final assembly" location is your front yard...not a controlled factory environment like in the automotive industry.

So...when designing systems for life safety protection of a building, why fully optimize? Is it worth a few dollars if life safety is at risk? Consider using systems that provide integrity to a fire resistance rated floor assembly (an intumescent firestop collar system) without relying on another fire rated element (rated wall) when making your life safety choices. Intumescent Firestop Collar Systems which do not rely on firewall integrity provide a much greater degree of protection to the occupant through reliable performance at the floor fire barrier regardless of fire resistance rated wall performance. Or, use the thicker depth firestop system "caulk only" designs on metal or insulated pipe designs. Even consider silicone sealant based firestop systems when water threat is possible for maximum protection. In the sealant designs, since much of the cost of the installation is labor, there really isn't a huge upcharge.

The minimum to meet code requirements may not be the best solution for the owner or public safety. Back up systems are a part of the space shuttle, why not life safety items we rely on everyday? Redundancy works for roofs...4 ply is better than 2 ply.....and lasts longer with more protection from the elements, human traffic and abuse. Don't we need protection using life safety items like firestops, fireproofing, fire damper assemblies, sprinklers, fire alarms and other fire protection items? Why do we need to make significant choices, "either or, active/passive"? Does all this "total optimization" work in a true fire condition, without the relying on another fire resistance rated element?

These very questions have been discussed and are part of the new International Building Code. There are significant trade offs made (reduction in use of passive fire protection) when active fire protection systems are used in buildings under the new code. Revisions to these new sprinkler trade offs to balance the approach to fire safety are already being discussed. Both active and passive protection systems are needed to maintain life safety standards in toady's buildings.

Building Firestop Systems to protect pipes, expansion joints and perimeter gaps in buildings is different than building a test assembly in a heated, inside laboratory. Over optimizing can cause a life safety risk by not allowing the field labor "room for error", whether intentional or not. The "margin of error" could be the constant creation of new penetrations in fire resistance rated assemblies after construction, active system troubles or maintenance.

Building codes provide guidelines to the designer on the "Minimum acceptable requirement" for building construction in a geographic area by building usage and type. Building occupants expect that buildings are completely safe for them to occupy....and exit if needed. Too much optimizing can cause life safety risks as we push the envelope of material technology's limits to remain competitive with our building costs globally. More important, do we want acturies deciding our fate in a fire, as we're trapped in a single exit room or dead end hallway due to optimized design? Do we want to become a mathematical risk calculation or have a safe way out?

With the labor quality of life safety Firestop Systems installations in mind, the Firestop Contractors International Association (FCIA) has developed a "Firestop Contractor Approval Program - FM 4991". This program, complete with a comprehensive exam on the Firestop Industry Manual of Practice taken by a firestop contractor firm's Designated Responsible Individual (DRI) functions much like an "ISO 9000" type program. The FM 4991 Firestop Contractor Approval process and verification audits will assure that contractors who perform Firestop Systems Installations have a quality program in place that reflects the Firestop Systems installation protocol.

FM Research, (Formerly Factory Mutual), Norwood, MA has administered the program for FCIA. This industry first "FM 4991 Firestop Contractor Approval Program", introduced at the FCIA Annual Meeting, Boston, MA last November, has already produced many FM Approved Contractors. These contractors are committed to a quality program that can help improve the accuracy of installed firestop systems to the tested and listed system or engineering judgment. By Specifying an "FM 4991 Approved Firestop Contractor", the architect can be assured that the following has already taken place:

  • DRI - The firm has employed someone who has passed a written examination on the firestop system installation protocol. The written examination is based on the FCIA "Firestop Industry Manual of Practice" handbook, available from FCIA.
  • Quality Manual - Each firm writes it's own quality manual reflecting policies and procedures that result in applications that reflect the tested and listed firestop system.
  • "Audited" - To become FM Approved, an FM Auditor visits the firestop contractor's office and a jobsite location to verify quality compliance to the quality manual.
  • Continual Audits - Once per year, an FM Auditor visits to verify continued compliance.

Whether it's active or passive fire protection systems, introducing quality programs to the industry, or promoting a more "balanced approach" to life safety, there must be thought given to these "optimization" issues. Optimizing life safety systems, to some degree, is needed to keep our buildings competitive in the world market. However, being too aggressive compromises life safety. Which building (school, office, high rise, hospital, hotel) would you rather be resting in, the highly optimized for both profit or something with a bit more "margin for error" should something go wrong? We'd hope the design professional took the time to really think through the fire protection plan and incorporated a great strategy for us to get out....quickly if we need to!

For more information on FCIA, contact the association office, 630/690-0682. Bill McHugh is an Architectural Sales Representative with Tremco, Inc., Roofing Division. He has experience as a firestop contractor, and spoken on the topic nationally. He was also part of the FCIA Technical Committee that wrote the FCIA Manual of Practice. Bill can be reached at 630.690.0682.

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Copyright, Bill McHugh, April 16, 2001