Interpretation #7492

Original Request

Code Version: 2010
Code: BUILDING
Code Description: Building
Chapter: 4
Section: 412
Topic: Fire suppression in Group III hangar

Question

I appreciate a recent interpretation of the code concerning the requirement to install fixed fire protection in all aircraft hangars. That was only part of the question. Since your reply confirmed that the code requires fire suppression designed in accordance with NFPA 409 and NFPA 409 does not provide design criteria for group III hangars where hazardous operations are not performed, how do we comply with the building code for fire suppression designed in accordance with NFPA 409 for group III hangars

Answer Published 05/12/2015 at 10:12 AM

The 2011 edition of NFPA 409 provides numerous
options for compliance when fire protection is
provided in Group III hangers (The 2011 edition is
appropriate as it is referenced in the currently
effective 5th edition FFPC.) Section 8.9.1 sends the
user to section 7.1.1 which provides four options
available for fire protection.

Commentary

This issue should be addressed with the local AHJ prior to any decision being made. FBC Section 412 refers the reader to NFPA 409. As the requester has pointed out, NFPA 409 does not provide design criteria for Group III hangars where hazardous operations are not performed. What is required by 409, however, is a "fixed fire protection system" where such a fire protection system is required by the local code. Aircraft hangars are FBC Group S-1 occupancies. FBC Section 903.2.9 establishes criteria dictating the conditions under which Group S-1 buildings need automatic sprinklers. If the 903.2.9 conditions dictate that sprinklers are required,then sprinklers are required. It appears that if the hangar is small enough, no fire protection system may be necessary. Further, NFPA 409, Annex A states, "Not all adopted building codes require fire protection systems in Group III hangars."