The shift to Ordinary Hazard Group 2, despite the fact that historically and statistically fires in parking garages have been effectively controlled under Ordinary Hazard Group 1, was driven by concerns about the increased combustibility of modern vehicles (plastics, synthetic interiors, larger fuel tanks), which make today’s fires potentially more severe compared to older parking facilities.
The question is: are the parking garages that have been protected for decades as Ordinary Hazard Group 1 now at greater risk? Evidence and fire records suggest not necessarily, since performance has remained acceptable. Still, it is reasonable to take a more cautious approach and apply Ordinary Hazard Group 2 for modern parking structures. However, extrapolating this reasoning to a fire station apparatus bay is not entirely valid. The context is different: * A safer overall design. * Fewer vehicles concentrated in the same space. * A very high level of care and maintenance applied by firefighters to their emergency vehicles, ensuring optimal operating conditions. Similarly, it is not appropriate to equate them with “machine shops” or “repair garages”, since no mechanical repairs or workshop activities are carried out in a fire station apparatus bay; its function is essentially parking and preparing the units. Therefore, based on the actual fuel load and use of the space, I believe an apparatus bay can be reasonably classified as Ordinary Hazard Group 1, since there is no mass storage of automobiles nor processes that increase the fire risk. That said, my view would be very different if we were talking about electric vehicles, where fire dynamics and stored energy would indeed justify a higher hazard classification. Finally, as a joke Let’s be honest: firefighters are not going to let their own truck catch fire… now that would be embarrassing! 😊 Saludos Cordiales Jussef Liban Gerente [cid:[email protected]] De: Fpdcdesign <[email protected]> Enviado el: miércoles, 8 de octubre de 2025 15:22 Para: Ken <[email protected]>; Discussion list on issues relating to automatic fire sprinklers <[email protected]> Asunto: [Sprinklerforum] Re: Fire station Remember, Standards (and Codes) are minimums, not absolutes. A hazard can be upgraded if warranted. Home Depot is not protected as Retail. Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080<tel:860-535-2080> (ofc) 860-554-7054<tel:860-554-7054> (fax) 860-608-4559<tel:860-608-4559> (cell) On Oct 8, 2025 at 3:17 PM, <Parsley Consulting<mailto:[email protected]>> wrote: Having a bit of confusion. A project is to follow the 2022 edition of NFPA 13. The apparatus bays of a fire station have been designated on the plan as ordinary hazard, group 1. When I look at the examples in §A.4.3.3.2, it seems to me that those spaces would be similar to (2) "automobile parking garages", or (14) "machine shops", or (24) "repair garages." This would make the space similar to ordinary hazard group 2, which increases the required density from 0.15 gpm/ft² to 0.20 gpm/ft². Am I looking this incorrectly? Any help greatly appreciated. sincerely, -- Ken Wagoner, SET Parsley Consulting 3002 Younger Drive Harrisonville, Missouri 64701-3909 Phone: (760) 745-6181 Visit the website<https://linkprotect.cudasvc.com/url?a=http%3a%2f%2fwww.parsleyconsulting.com%2f&c=E,1,Y5zKJKPEh1mBEBqSR-VE9cUKl5y-eyP8BpvmE_5j9ZqW2eJbNphYzrCMBZ-2YuX6d-RRkHI4gQ1FV-cvOeCfRC58uZS9NiToZv2mx7909oCqLvCW_n5hDHeK&typo=1> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]<mailto:[email protected]>
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