Extra Protection for Cultural Resources
NFPA Journal®, November/December 2007
By Russell P. Fleming, P.E.
NFPA 909, Code for the Protection of Cultural Resource Properties – Museums, Libraries and Places of Worship traces its history back to a 1948 NFPA document: Protecting Our Heritage.
During the past 60 years, the NFPA has merged various recommended practices and guides into a comprehensive set of requirements aimed at providing fire safety for culturally significant structures and their contents. Automatic fire sprinkler systems have played an increasing role over the years; the current 2005 edition of NFPA 909 requires automatic sprinkler or alternative fire suppression systems for all new construction. The Technical Committee on Cultural Resources also writes NFPA 914, Code for Fire Protection in Historic Structures, which recommends the use of automatic sprinklers.
Many culturally significant properties are protected with simple wet pipe sprinkler systems, appreciated for their performance and reliability. For example, the rare book stacks at the U.S. Library of Congress are protected with clean agent gas extinguishing systems for first strike capability, but these important items are also newly protected with standard wet-pipe automatic sprinkler systems.
Because cultural resource properties often contain rare or irreplaceable collections, the appreciation of sprinkler systems is accompanied by a desire that special efforts be made to ensure and enhance their reputation as reliable and trouble-free systems. NFPA sprinkler standards are therefore viewed as reasonable minimum standards to which the special concerns of the preservation community can be added. For example, although NFPA 13D, Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes is the standard applicable for such sized dwellings in preservation community sites, NFPA 914 specifically allows the use of the systems described in NFPA 13, Installation of Sprinkler Systems for these dwellings in recognition of the superior property protection afforded by the parent standard.
Beginning with the 2005 edition, NFPA 909 also made an exception to NFPA 13, allowing the use of standard-response sprinklers in light hazard areas of cultural resource properties. Annex wording in the document points out that standard-response sprinklers employ more robust operating elements than fast-response sprinklers and may be more appropriate for use in areas where concern for inadvertent water discharge outweighs the advantages of thermal sensitivity. This same allowance is made in the 2007 edition of NFPA 914.
The NFPA Cultural Resources Committee initiated the recent change to NFPA 13 that requires the pitching of pipe in preaction systems even where the piping is not exposed to freezing. Preaction systems are those in which piping is normally filled with air and require the operation of both a separate detection system and automatic sprinklers before water is released onto a fire. While some museums and libraries endorse the use of preaction sprinkler systems on the basis that they are less likely to result in unwanted discharge of water, these systems can still react negatively to neglect or poor installation. The lack of proper drainage has been found in some cases to result in premature pipe corrosion. Even though NFPA 13 has made the change to require pitching of pipe in its 2007 edition, the Cultural Resources Committee recently pursued an emergency Temporary Interim Amendment (TIA) to its own 909 document to alert users that might be installing sprinkler systems in accordance with earlier editions of the sprinkler standard. The TIA also called for other enhancements aimed at preventing corrosion, such as the use of internally galvanized Schedule 40 steel piping for dry and preaction systems. The entire area of corrosion prevention will receive additional work as the next edition of NFPA 909 is prepared.
All of these special rules are in recognition of the published scope statements for the NFPA sprinkler standards. The standards provide minimum requirements for a reasonable degree of protection. In the case of historic properties and cultural resources, a higher degree of protection is often warranted.
Russ Fleming is the Executive Vice President of the National Fire Sprinkler Association and a member of the NFPA Technical Correlating Committee on Automatic Sprinklers.