Growing up I watched stock cars run on a dirt track and then for a summer I followed a driver and his car from track to track sometimes seeing three nights of racing a week. Now, almost fifty years later I watch NASCAR and Indy cars and go to races when I have an opportunity.
Forty years ago I started designing fire sprinkler systems. I was intrigued at the time and tried to follow the rules in the “Red Book”, (National Fire Protection Association, Standard 13, Installation of Sprinkler Systems, 1975). I followed the rules to the point where the fitters I worked with would ask me to assist them with their apprenticeship and test preparation. Now, forty years later, I still follow the rules and try to teach the same wherever the opportunity arises. As part of my professional life I investigate losses involving fire protection systems and perform the review of contractor submittals for sprinkler system design; in addition to writing with four colleagues, and presenting classes, through the Society of Fire Protection Engineers, entitled Sprinkler Design for Engineers, and Protection of Storage Occupancies.
I’ve operated Futrell Fire Consult & Design, Inc. that is a Fire Protection Engineering firm staffed with NICET Engineering Technicians, Senior Engineering Technicians, and Fire Protection Engineers for the last twenty-five years. One of the fire protection engineering services we provide is the plan review of sprinkler systems for municipalities and other engineering firms and we try very hard to follow the design and installation standards that the code officials have adopted.
What do these two passions have in common? Rules.
Some time ago, while watching the “Indy” car race from Chicago, I heard that a car and driver were fined and penalized because their car was out of tolerance by a “couple of thousandths of an inch”. It immediately occurred to me that they were deceitful, or cutting corners, to get an unfair advantage and it was in the thousandths of an inch range. Then, because it really bothers me, I began to think of the conversation I had earlier with another fire and life safety professional who told me that I was “too picky” requiring, through the sprinkler system plan review process, sprinkler designers to design the sprinkler systems within the rules of the National Fire Protection Association (NFPA) Standard 13, “Standard for the Installation of Sprinkler Systems”. He pointed out that standard sprinklers will cover more than fifteen feet and therefore if the designer chooses to design the system with sprinklers spaced more than fifteen feet on center or more than seven feet six inches off the wall (one half the allowable distance for standard sprinklers) the sprinklers will still provide adequate protection, or coverage, in his opinion.
In many states, the International Building and Fire Codes are adopted as a state Statute and generally speaking they refer to NFPA 13 as the design standard for fire sprinkler systems. If sprinkler system designers, or the plan reviewers, use the established standard (rules) for the sprinkler system design, then they should follow the rules in the standard. However, if the designers and plan reviewers aren’t going to use these adopted guidelines then maybe NFPA 13 should be modified to include new terminology such as “usually 15 feet maximum spacing”; “approximately one half the distance between sprinklers”; or “about a minimum of six feet between sprinklers.” I can certainly extend this to other aspects of sprinkler system design such as, “almost a Group A plastic”, or “approximately 0.10 gallons per minute for the design density”, design areas, Early Suppression Fast Response sprinklers and obstructions, and so on in another article, but this article is about sprinkler spacing.
This concern of mine isn’t limited to fifteen feet between sprinklers and seven feet six inches off of walls, but to all spacing rules (standard sprinklers, extended coverage sprinklers, special sprinklers, and residential sprinklers). All of these sprinklers have specific spacing requirements in either NFPA 13 or indirectly from NFPA 13 through the manufacturer’s product literature. For one example, the minimum spacing between residential sprinklers is 8 feet. In our plan review of sprinkler system designs we’ve observed spacing of 6 feet to 8 feet between these specific residential sprinklers. Another fire and life safety professional said, “They probably can’t get them eight feet apart because of the studs.” How does the designer know the studs are in the way? He/she as the designer is looking at a set of architectural plans and can put them in a different location or on an adjacent wall in almost every case. Of course that might add a sprinkler (sure multiplied by typical rooms and floors it can be quite a few), but not always, and we know adding sprinklers increases the cost of the sprinkler system. Or, how about not allowing a sidewall sprinkler in the spray pattern of another sprinkler, or that residential sprinklers are supposed to wet the walls to within 2’-8” of the ceiling? All of these are special concerns that need to be included in the design process, but are frequently overlooked.
It should not be the plan reviewer’s fault that the sprinkler designer didn’t take the time to design it correctly, or maybe the estimator didn’t estimate it properly. It is possible the designer wasn’t properly trained, and it is most likely that no one in the designers office performed a thorough in-house review of the design before it was submitted.
From the fire and life safely professional’s perspective, should they allow the modification of spacing rules because designing and installing in accordance with the adopted standard will cost more? I should hope not. We should start with the premise that the sprinkler system needs to be designed and installed in accordance with the current code and standards, and not base it on what has been acceptable in another time or another community.
So, back to my analogy, it is troubling to me that with rules established and adopted for public safety, in a life safety, property protection, firefighter safety scenario it’s not only acceptable, but advocated by some fire and life safety professionals to exceed the rules regarding the spacing of automatic sprinklers used for fire and life safety. What is his or her liability or their validation for deviating from the codes and standards? While on the other hand, it’s a fine and penalty to exceed the height of the spoiler on a race car by a couple of thousandths of an inch! A designer should strive to meet the requirements regarding spacing of sprinklers for the minimum design standard. NFPA 13 is the minimum standard. I am not writing about Fire Protection Engineers providing a design analysis; creating a performance-based design; and validating a design concept, I am specifically writing about sprinkler system designers, sprinkler pipe fitters, and other fire and life safety professionals changing the minimum rules in NFPA 13 to suit their needs.
I’d like to know, because the rules are fifteen feet maximum and no more than seven feet six inches off a wall for standard sprinklers, what is really acceptable to these designers and fire and life safety professionals and what do they base those determinations on? Do they have fire tests that indicate, in all scenarios, exceeding the NFPA 13 or manufacturer’s spacing limitations is acceptable or will have acceptable results? Is it okay to design a sprinkler system with the sprinklers spaced fifteen feet two, three, or six inches apart? If so, why? Is there an upper limit where the spacing is too far?
I fully understand that there may be field conditions (structural members, and so on) that may require minimum field adjustments, but why should a designer start the design exceeding the code maximums, or minimums, in any case, and why should pointing that out be overly picky? The International Fire Code gives the Authority Having Jurisdiction the ability to make necessary modifications for conditions encountered in the field, but that should not happen in the design phase of new construction.
It would seem that if the rules were enforced consistently some of the conflicts between designers and reviewers would be eliminated. But if fifteen feet isn’t fifteen feet in one community, and it is in another, someone will not be happy.
By the way, NASCAR had the same issues at Daytona that year and those teams were fined and the crew chiefs were suspended. These types of rules infractions are looked for before and after every race. Sprinkler system design deficiencies are often only found when the sprinkler system does not perform as expected in a fire condition.
Now let’s take this one step further and include inspection, testing, and maintenance of sprinkler systems. NFPA 25, the Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems starts with the basic assumption that fire sprinkler systems have been designed, installed, inspected, and tested in accordance with NFPA 13. If a sprinkler system has been installed that is not in accordance with NFPA 13; see the discussion above, what does NFPA 25 say about that? Nothing. That is another article, but keep in mind that if the systems aren’t designed and installed properly to start with, nobody is taking the responsibility to make sure they get fixed. Indy cars and NASCAR inspect everything, every race with a fine tooth comb; and if you’ve ever watched those inspections you know it is significantly more technical than a fine tooth comb! Fire and life safety sprinkler systems are often not carefully or thoroughly reviewed or inspected until after one of them fails for some reason.
ABOUT THE AUTHOR: Scott A. Futrell, PE, FSFPE, CFEI, CFPS, SET is a fire protection consultant with Futrell Fire Consult & Design, Inc., in Osseo, Minnesota. He is a co-author of “Designers Guide to Automatic Sprinkler Systems” available from the Society of Fire Protection Engineers.