The fire marshal was probably thinking of the definition in NFPA 101 : Life Safety Code, which takes “hazard” to mean “threat to life.” The marshal was incorrect as far as NFPA 13 is concerned- for sprinkler systems, “hazard” means “severity of fuel load.”Īs long as a room meets the hazard, construction, and size requirements, the small room rule can be used. NFSA once received a question from a member who was told by their state fire marshal that they could not use the small room rule for nursing home bedrooms because the threat was not “light hazard.” The confusion arose because there are different uses of the term “hazard” in different codes and standards.

The exact definition of “light hazard” occasionally causes confusion. Thus, the standard allows sprinkler designers some leeway in these circumstances. And the NFPA 13 Handbook explains that “Fires in small rooms of a light hazard occupancy present a lesser challenge to the sprinkler system” because of their small size and low fuel-load. NFPA 13 explicitly calls such an area a “small room” (3.3.196 2019 edition). When does NFPA 13 allow the small room rule?ĭesigners can apply the small room rule for any compartment that is: Join NFSA today or renew your membership online to access these resources and much more. Members can also build their skills and work towards certifications with their access to NFSA training and seminars offered online, in-person, and in blended settings. Through NFSA’s Expert of the Day (EOD) service, NFSA members get answers to their toughest questions from fire sprinkler experts. Read on for a detailed exploration of these questions! Note: All references from NFPA 13 in this piece are referencing the 2019 edition of the standard. How does the small room rule affect hydraulic calculations?.What sprinklers can be used with the small room rule?.How can the small room rule be applied?.When does NFPA 13 allow the small room rule?.NFSA’s Expert of the Day service has answered many questions about using this provision, so we’ve put together some FAQs about the small room rule, including: It simplifies certain area-of-coverage and sprinkler placement requirements for easy-to-protect “small rooms.” But while the rule is pretty straightforward, even a simple section on paper can create confusion in practice. Most sprinkler designers know about and use the small room rule found in NFPA 13 : Standard for the Installation of Sprinkler Systems.

Common issues when evaluating and applying the fire sprinkler small room rule

Small room design layout