Jacqueline Wilmot: The vehicle storage puzzle
The ins and outs of fire protection in parking garages.
What type of structure experienced an annual average of 6,000 fires in the United States between 2013 to 2017?
Here’s a hint: The same structures that contain petroleum fuels, as well as alternative fuel, plastic, synthetic materials and electric charging equipment.
The answer is parking garages.
Over the past 60 years, automobiles have evolved to meet consumers’ needs in a variety of ways, including an increase in fuel efficiency by replacing metal parts with plastic ones to produce lighter vehicles. In addition to the change in manufacturing materials, technology advanced to create a platform for alternative fuel vehicles for more environmentally-friendly customers.
Meanwhile, parking garages — the structures that house these vehicles — have essentially remained the same, with the exception of the automated parking structure (more on that later). One could argue that one of the biggest changes for parking structures is the potential new fire hazards and demonstrated fire signature they carry.
The Kings Dock Car Park, located in Liverpool, England, contained an eight-story open-air garage that could hold about 1,200 vehicles. A fire that took place in the garage on New Year’s Eve in 2017 resulted in the destruction of more than 1,200 vehicles. Fortunately, while no lives were lost (most likely due to the timing of the fire), this incident initiated a global discussion on the existing fire protection of parking garages.
Current requirements for protecting garages?
As always, check with your authority having jurisdiction to determine which code is being enforced by your jurisdiction.
If your jurisdiction enforces NFPA 1, Fire Code, the latest edition of this code (2018) requires fire protection of new and existing parking garages. In addition, the code requires the control of hazards in open parking structures, enclosed parking structures, and basement and underground parking structures to comply with Chapter 29 of NFPA 1 and Section 42.8 of NFPA 101, Life Safety Code, 2018 edition.
Section 42.8 in NFPA 101 addresses the life safety requirements for parking garages (structures). This section includes extracts from NFPA 88A, “Standard for Parking Structures.” This document provides the minimum requirements for the construction and protection of, as well as the control of hazards in open and enclosed parking structures.
NFPA 88A requires automatic sprinkler systems to be installed in enclosed parking structures located at or above grade, within or immediately below a building that is used for another occupancy. In addition, automatic sprinkler systems need to be installed in portions of enclosed parking structures, the ceilings of which are less than 24 inches (600 mm) above grade, regardless of the type of construction, and in enclosed parking structures of Type III or Type IV construction over 50 feet (15 m) in height. The automatic sprinkler systems need to conform to NFPA 13, “Standard for the Installation of Sprinkler Systems.” Automatic sprinkler systems are not required in open parking structures (see Section 5.5 of NFPA 88A).
How does NFPA 13 tell you to design and install a sprinkler system for this type of occupancy? Section 4.3.3 of the 2019 edition of the standard lists automobile parking as an example of an Ordinary Hazard Group 1 occupancy, which consists of spaces with moderate quantity and low combustibility of contents, and stockpiles of contents with low combustibility that do not exceed 8 feet (2.4 m). The system designer needs to remember that NFA 13 lists examples of occupancies only, and additional consideration needs to be given to the specific automobile parking he/she is responsible for protecting. For example, if there is an entire section of a parking garage dedicated to electric cars or where car chargers are present, that could indicate a higher level of protection needed.
NFPA 13 also addresses car stacking systems or car lift systems with a maximum of two automobiles high as Extra Hazard Group 2. This includes spaces with very high quantity and combustibility of contents, spaces with substantial amounts of combustible or flammable liquids, as well as spaces where shielding of combustibles is extensive.
If your jurisdiction enforces the International Building Code (IBC) or the International Fire Code (IFC), these documents require an enclosed parking garage to be equipped with an automatic sprinkler system in accordance with Section 903.2.10. This section addresses Group S-2 Enclosed Parking Garages, and requires automatic sprinkler systems to be provided throughout the building classified as enclosed parking garages in accordance with Section 406.6 where either of the following conditions exists:
- Fire area of the closed parking garage is greater than 12,000 square feet (1,115 square meters);
- The enclosed garage is located beneath other groups unless the enclosed garage is located beeath group R-3 occupancies; or
- Commercial parking garages require an automatic sprinkler system to be installed throughout buildings used for storage of commercial motor vehicles where the fire area exceeds 5,000 square feet (465 square meters).
Are existing standards good enough for the ‘new’ hazards that did not exist in parking garages when most of them were built? This is the question many industry experts are now asking. The Technical Committee responsible for developing NFPA 13 recently removed parking garages from the list of Ordinary Hazard Group 1 occupancies at the First Draft Meeting. The reason for this change is because the materials used for auto-mobile construction have changed so much that the hazard has moved beyond that of Ordinary Hazard Group 1. The Technical Committee needs additional information on the burning characteristics of the newer vehicles and their impact on parking garages to establish a more reasonable hazard classification.
What information are we missing? Do we need to increase the minimum fire protection requirements for these structures, and if so, how? Earlier this fall, the Fire Protection Research Foundation (the research affiliate of NFPA) posted the project summary for “Modern Vehicle Hazards in Parking Garages and Vehicle Carriers.” The purpose of this project is to quantify the fire hazard of modern vehicles in parking structures and vehicle carriers to provide guidance to technical committees.
This project contains a literature review and hazard assessment, while assessing existing design critiera, developing guidance and identifying remaining knowledge gaps. This report is estimated to be completed by Spring 2020.