What It's All About
The importance of the scope and purpose statements in the automatic sprinkler system installation standards. BY MATT KLAUS
I AM ALWAYS AMAZED WHEN I hear users of codes and standards say that they don't read the scope and purpose statements in Chapter 1 because they claim to already know what the standard is about. While the scope and purpose statements in some documents are fairly straightforward, many others contain nuances that are critical for the correct application of the standard.
Understanding the scope and purpose of the three NFPA automatic sprinkler system installation standards is essential for selecting the correct system for a particular occupancy and also for the needs of the owner. The oldest of these standards, NFPA 13, Installation of Sprinkler Systems, has been in print since 1896 and was established to standardize how sprinkler systems were designed and installed. At that time, there were as many as nine different methods used for the design of these systems, resulting in widespread confusion among the plumbers who installed them. Fearing that the confusion would lead to poor installation practices and, eventually, poor system performance during fire events, the Boston office of the Underwriters Bureau of New England created what is now NFPA 13 as a property protection standard.
As the standard evolved and sprinkler systems became required in both commercial and residential occupancies, the scope and purpose became twofold: property protection and life safety. NFPA’s residential sprinkler system installation standards—NFPA 13D, Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, and NFPA 13R, Installation of Sprinkler Systems in Low-Rise Residential Occupancies—were first issued in 1975 and 1989, respectively. These documents were conceived as a way to provide automatic sprinkler system protection in residential occupancies that, at the time, were not required to have them. This included low-rise residential occupancies such as hotels and apartments, as well as single-family residences. In order to get the standards referenced in model building codes, there had to be significant differences between them and their big brother, NFPA 13.
While the intent of NFPA 13 is to protect property, the primary purpose of NFPA 13R and 13D is to provide life safety. That purpose allows for the omission of sprinklers in attics, closets, and other concealed spaces—an aspect that alters a system’s property protection capabilities while having little or no impact on the system’s protection of life safety. Fires starting in kitchens, bedrooms, and living rooms will likely be controlled without the fire spreading beyond the room of origin.
Recently, there have been a number of “total loss” fires in buildings protected by NFPA 13R systems. No lives were lost in these fires, which demonstrates that the sprinkler systems did what they were intended to do. Even so, problems arose because some of the property owners, and in some cases the system designers, did not understand that an NFPA 13R system does not match the property protection capability of an NFPA 13 system. While an NFPA 13 system is not required for many low-rise residential occupancies, many owners are opting to go beyond the minimum of NFPA 13R by installing NFPA 13 systems, with the goal of maximizing property protection. This decision can only be made where the design team, including the architects, owners, and system designers, understands the scope and purpose of the standards.
Not having a clear understanding of the scope and purpose of the sprinkler standards has cost some building owners a lot of money—in some instances, it’s even cost them their buildings. It is important for engineers and system designers to understand the purpose of the sprinkler standards, and to be proactive with owners and design teams in explaining those differences.