Letters to the Editor
Defeating the Firestop” draws discussion of foam insulation use and fire spread
I’m writing this letter in response to George Howard’s Training Notebook article, “Vertical Foam Insulation: Defeating the Firestop,” in the May issue. I feel I’m qualified to respond to several misconceptions expressed by Lt. Howard in that article because I’ve been a full-time career firefighter for the City of Concord, N.H., for the past 10 years and a contractor in the same community for the past six years.
First, Lt. Howard states in the article’s title that exterior foam insulation defeats the firestops of a building’s interior framing. With all due respect to Lt. Floward, one has nothing to do with the other. Interior firestops, also known as plates in platform-type construction, are installed to prevent fire from traveling vertically in the void spaces between sheathing and Sheetrock (a major improvement to the balloon-type construction of the early 1900s). Only the breaching of these stops on the inside of the wall sheathing by pipe channels or wiring accesses can defeat the firestop’s effectiveness.
Nothing that occurs outside of the wall sheathing or inside the interior gypsum board will affect the firestop until the time that a “core burnthrough” occurs. When this burnthrough takes place, the firestops are no longer effective in preventing vertical fire spread. Foam insulation will increase the flame-spread rate on a building’s exterior if a burn-through occurs or if a wall is exposed to an exterior fire, but the same can be said for wood exterior siding (clapboard) or asphalt siding.
These types of insulation applied behind aluminum siding can create a hidden, exterior path for fire that’s rapid and very difficult to detect, but the same cannot be said for foam and vinyl siding. Vinyl siding will melt and fall long before there’s sufficient heat or flame spread to create a burn-through from the exterior to the interior of a building with wood sheathing properly installed.
The uses of foam insulation in the construction and siding industry should be of great concern to us, but not for the reasons stated by Lt. Howard. More serious hazards are created by the use of thick (two inches and thicker) foam panels (polyisocyanurate foam sheathing boards) as the sole exterior sheathing that’s applied to buildings that also contain wood truss floor joists and rafter assemblies. This application, in conjunction with the use of vinyl siding and/or wood roof shingles, presents the greatest construction-related firefighting hazard today. These buildings have no exterior resistance to fire or heat, and any breach in the interior, gypsum-board walls will cause an immediate core burnthrough. The products of combustion that are produced by the polyvinyl chloride and polyisocyanurate are extremely toxic, but the flame spread rate of the materials is such that a rapidspreading, short-burning exterior fire will occur, instead of the deep-seated, slow-burning fire that occurs with wood sidings.
Lt. Howard is correct in stating that exterior foam insulation constitutes a fire and health hazard to today’s firefighters, but not because of its ability to spread fire past firestops. All combustible exterior siding, as well as interior decoration materials such as paneling or wallpaper, will spread flame past the firestops, but it does so outside of the exterior wall sheathing. This exterior spread doesn’t constitute an increased fire danger to the inside of a building unless a core burn-through occurs. Once this bum-through has occurred, regardless of the materials involved, all bets are off on the effectiveness of firestops, as flame spread occurs outside of the boundaries they were designed to protect.
David A. Reed
Firefigh ter/EMT-1
City of Concord Fire Department
Concord, N.FI.
George Howard responds:
Firefighter Reed makes a valid point as to the physical burn-through of the firestopping. However, as he himself points out, it’s possible for fire to spread vertically by means of the various foam insulations. Therefore, a fire is allowed to pass around the firestop rather than through it. That basically defeats the purpose of the firestop. While the physical firestop may still be intact, the fire may be burning all around it. What’s more important, however, as Firefighter Reed also agrees, is that we in the fire service must readily understand the different types of foams, their hazards, and the problems they present to us, and we must avoid a myopic approach to the subject.
To join or not to join professional organizations: The issues are clout…
1 applaud you and your July editorial, “Where Are You, Chief?” You are right on the money. The fire chiefs of our nation appear to be ignorant of the need to be part of our professional organizations and the role that these play in accomplishing the goal of a tire-safe community. The other possibility is that fire chiefs are indifferent to the importance of a unified voice.
Being politically active is often viewed in a negative fashion. However, joining a national organization, such as the IAFC, and supporting it, both financially and emotionally, offer fire chiefs the opportunity to be politically active without having to take an active leadership role.
If we are to accomplish our mission of providing a fire-safe community for all citizens, we must be unified; we need a central voice which can and will speak out when the time is right. We also need clout in the form of a large membership and ample funds. Our professional organizations give us the opportunity to achieve this.
There is strength in numbers, and, yes, as you’ve indicated, strength begets numbers. But I believe even more important is to recognize that organizational strength begets results.
James J. Murtagh Deputy Chief
Fire Department of New York City Brooklvn, N. Y.
Department works toward fire prevention through aggresive ordinance revisions
The article “A sprinkler ordinance that’s short and sassy” [see Dispatches in the June issue] has prompted me to write to you. At the risk of “tooting our own horn,” 1 feel it’s time for me to speak out about the accomplishments of the Longboat Key (Fla.) Fire Department in the field of fire prevention over the past 10 years.
Our first ordinance adoption in 1977 has three major sections which, at that time, were considered very innovative:
- Install sprinkler systems in all buildings three stories or higher;
- Require automatic fire alarm systems to be installed in all buildngs three stories or higher or consisting of 10 or more units; and
- Require smoke detectors to be installed in all newly constructed residential buildings, including singlefamily occupancies.
In 1981, we updated our code with some major changes. Under the revised code, all buildings, including townhouses, had to be sprinklered. The only exception was single-family residences. We changed our fire alarm ordinance to say that all required systems had to be hooked up to our dispatch center. We also required a minimum of one battery-operated smoke detector in all sleeping areas in new and existing buildings, including existing single-family residences. We added many other sections at this time. These included fire prevention code, emergency access, key box systems, and malfunctioning fire alarms.
In 1986, we made our latest update, which says all newly constructed buildings must be sprinklered. This includes single-family dwellings. All buildings are required to have an automatic fire alarm system hooked up to a dispatch center. A retrofit section requires an automatic fire alarm system to be installed in buildings three stories or higher. A dry-pipe standpipe system must be installed in existing buildings three stories or higher. We require all alarms, sprinklers, standpipes, and fire pumps to be inspected by a licensed contractor. We plan to continue to submit requests to our commission for retrofit sprinklers.
We were able to accomplish our goal through public education and awareness with the facts and figures to back us up. We also consulted all relevant groups: developers, builders, contractors, citizens’ groups, civic organizations, realtors, and anyone else who would listen. If you don’t do that, you can forget it.
Robert J. Mazza
Captain/Fire Marshal
Longboat Key Fire Department
Longboat Key, Fla.
Reader requests sprinkler retrofit information
I enjoy reading Fire Engineering and have been a subscriber for many years. I’d like to gain additional information on the article “Standing Firm on Sprinkler Retrofit” by Robert D. Nielsen in the June issue. In reading Lt. Nielsen’s article, I found that his department’s fire prevention bureau is very active and progressive in its duties.
The Wescosville (Pa.) Fire Department provides protection fora community of 15,000 people. We’re in a largegrowth area, with most of our commercial activity just starting.
We’d like some assistance from Lt. Nielsen’s and any other departments that might be able to give us information. Lt. Nielsen states that his department uses the American Insurance Association Fire Prevention Code and NFPA 101 Life Safety Code. Perhaps he could provide some information about the following:
- Fire protection (sprinkler, standpipe, and fire-detection systems) for apartment and office buildings ranging from three to seven stories;
- The location of detention ponds in relation to buildings;
- Whether his department reviews all development plans; and
- Whether his department reviews all building plans for compliance with sprinkler, standpipe, fire-detection, and life-safety requirements.
We’d greatly appreciate any relevant information that Lt. Nielsen and any other departments could provide. We’ll be using this information to update our fire prevention codes.
Brent A. McNabb
Captain
Wescosville Fire Department
Wescosville, Pa.
Lt. Nielsen responds:
- There are no multifamily residences in Oak Brook, III. The bulk of the village is offices, and they’re required to be sprinklered.
- Because of the freezing weather our region experiences, we frown on the use of detention ponds to supply water to protection systems. All of our sprinkler systems are fed by the municipal water system.
- We review all development plans.
- And we review all building plans for the compliances you mention. Our building and fire code inspectors are consolidated into one agency, so we work together very well.
…and the rising cost of membership
In your July editorial, “Where Are You, Chief?,” you chastise the chiefs who fail to join the IAFC or attend the association’s meetings in St. Louis.
Most departments barely have enough money in their budgets to buy hose and turnout gear. And if NFPA 1500 goes through, funds will be even more scarce. Indeed, our department is so short on funds, we haven’t sent a chief to the New York State Fire Chief’s convention in several years.
I’m a member of the IAFC because I personally foot the bill. However, according to this month’s IAFC On Scene, the IAFC board has proposed increasing the annual dues by S25. That puts it out of my league, and I’ll bet you a dozen donuts your figure of 7,000 members will decline accordingly.
Alan T. Price
Assistant Chief
Point Pleasant Fire Department
Rochester, N. Y.
