Is bigger better?
By Samuel S. Dannaway, PE,
President, S.S. Dannaway Associates, Inc., Honolulu
My first exposure to Pamphlet 13 came during my college years, with the 1974 edition of NFPA 13, or what old timers called the Red Book. It was 171 pages in length. The pages were 5 inches by 7 ½ inches, and it would fit in your back pocket. The 2010 edition of NFPA 13 (in which the cover is finally, once more, that legendary red color) contains 421 8½-inch by 11-inch pages. This comparison is a little unfair, as NFPA 13 has absorbed requirements from other standards that have increased its contents, such as NFPA 231, 231C and others.
Was this substantial page inflation necessary to achieve the considerable improvements in life safety and property protection that have been achieved through sprinklers since then? I do not have the answer to that, but I will note that sprinklers have been doing a pretty good job for more than 100 years.
While many fire protection engineers are promoting the benefits of performance-based design methods, our sprinkler standard is becoming a prescriptive nightmare. I understand that, with the advent of hydraulically designed systems in the ’70s, NFPA 13 started to lead fire protection engineering out of the prescriptive wilderness to the city on the hill of performance-based design method.
Granted, with performance-based fire protection engineering design, there will always be a need for prescriptive standards. The prescriptive requirements for stair design are a good example. No need to reinvent the wheel there. The same goes for NFPA 13, which, except for its discharge design criteria and hydraulic design, is almost entirely a prescriptive standard.
Most of 13’s prescribed requirements are important and necessary. What concerns me is the continuous tinkering with the standard in the hopes of prescribing solutions for the entire universe of situations. We all know that the major criticism of prescriptive codes and standards is that they cannot cover all possible conditions. Yet, that is exactly what people spend a lot of time doing in their attempts to “improve” the standard. (Have you tried to apply the sprinkler obstruction rules lately? If not, please see the article in the October 2009 edition of Plumbing Engineer. You may still be confused, but do not worry; I wrote the piece and still have trouble with 13’s obstruction rules).
Many of the proposals I see coming to the committee that I serve on deal with trying to make a situation absolutely crystal clear so a particular authority having jurisdiction (insert the name of your favorite AHJ here) will not be able to misunderstand the requirement and force some onerous and unnecessary provision on the engineer, the contractor or the owner. I do not believe the standard is intended to be changed for this reason. We all have our AHJ stories to tell, and I am sure the AHJs have theirs. But there is one thing I am certain of; if an AHJ is prone to misunderstanding or misapplying provisions of NFPA 13, it is highly unlikely that solving one problem with more text in the standard will correct the situation. Like a whack-a-mole, once you have pounded one problem down, another one will pop up.
Rather than try to change the code or standard to deal with these issues, our time would be better spent educating the AHJ. Getting involved in the education of code enforcers has multiple positive effects. First, you get to know the person better and perhaps get a feel for their issues and concerns. It can help to develop trust between the AHJ and the engineer or contractor. When AHJs know that you are not going to feed them a load of bull, good things can happen. There are many ways to accomplish this, such as inviting them to a meeting of the local SFPE chapter, sharing articles with them or bringing in manufacturers to discuss new products and technology. If you want to go all out, you could organize a seminar and offer special rates for code enforcers. The goodwill created from providing these educational opportunities is priceless.
But I digress. The point of this article is to question whether or not the continuing expansion of 13, or any other code or standard, with each new edition is a good thing. Maybe the revision cycle should be lengthened from three years to four or five years to slow the rate of page inflation. Maybe code change proposals should be limited to items of an emergency nature or for the introduction of significant new technology.
Another concern I have is that, in addition to page inflation, each new edition seems to bring its share of sprinkler system price inflation. Increases in cost take the form of additional time to prepare shop drawings, additional time for engineers to review the submittals, additional cost for new required components. It may be wise to require that all code change proposals include an analysis of the impact of the cost of the proposal. Those of us who sit on technical committees or who write proposals (especially those that are paid to write proposals) need to do some reflection. Is bigger really better?
Maybe, it’s naïve of me to think the standard can be improved by reducing the total number of words. I think we must make the effort, as I do not have a back pocket big enough to carry a two-volume version of NFPA 13.
Update on antifreeze: NFPA has issued four new Tentative Interim Amendments (TIAs) on the use of antifreeze in sprinkler systems. TIA 10-2 log 1015 pertains to NFPA 13, TAI 10-2 Log 1012 pertains to NFPA 13D, TIA 10-2 Log 1013 pertains to NFPA 13R, and TIA 11-3 Log 1014 pertains to NFPA 25. The effective date of these TIAs was March 21, 2011.
The 10-2 TIAs replace the August 2010 TIAs 10-1, which had imposed a moratorium on the use of antifreeze in dwelling units. These new 10-2 TIAs apply to all new sprinkler systems, not just those in dwelling units. Only factory premixed solutions of antifreeze may be used, and antifreeze solutions are limited to glycerin not exceeding 48% by volume and propylene glycol not exceeding 38% by volume
TIA 11-1 for NFPA 25 contains similar requirements for existing sprinkler systems. Existing antifreeze can remain in place if it can be identified as either glycerin or propylene glycol, in concentrations that do not exceed 50% by volume for glycerin and 40% by volume for propylene glycol and if it does not require modification. Testing of the antifreeze at up to four locations is required as follows: the top of the system, the most remote point of the system (if not at the top), the bottom of the system and at the water supply connection (if not at the bottom of the system).
Use the following links to get all the details of these TIAs:
Samuel S. Dannaway, PE, is a registered fire protection engineer and mechanical engineer and past president and a Fellow of the Society of Fire Protection Engineers. He is president of S. S. Dannaway Associates, Inc. He can be reached via email at SDannaway@ssdafire.com.