Tire Carousel Fire Protection: NFPA 13 Compliance Strategies

Overview

Tire carousels in automotive dealerships and repair facilities present a unique fire protection design challenge. These rotating storage systems—typically 18' x 8' footprint with heights approaching 20'—create storage configurations that trigger excessive water supply requirements under current NFPA 13 editions. The core issue: Tire storage classification as High Hazard commodity under NFPA 13 (2016 and earlier since at least 2013) Section 23.4.4.2.4 mandates a minimum 3000 GPM design density, regardless of the actual footprint area. For facilities previously designed with 300 GPM (OH2) systems, this represents a 10x increase in water demand for what may be only 150 square feet of storage.

The Problem: High Hazard Classification

Tire carousels fail to qualify as miscellaneous storage under NFPA 13 18.4(a) Exception #5 because of their height. The vertical configuration pushes total storage height beyond the 12-foot miscellaneous storage threshold, compelling classification as high piled storage per Section 18.4. Under NFPA 13-2016 Section 23.4.4.2.4, facilities with tires stored at heights exceeding 12 feet must provide sprinkler systems capable of delivering minimum 3000 GPM to the design area. This applies regardless of:

• Actual carousel footprint (often only 150-180 sq ft)
• Building occupancy classification
• Existing water supply capacity
• Other fire protection systems in place

Code Analysis: Applicable Standards

Code Section	Requirement	Application
NFPA 13 (2016) 23.4.4.2.4	3000 GPM minimum flow for high hazard tire storage	Primary design driver
NFPA 13 Table 18.4(d)	ESFR sprinkler water demand by hazard	Alternative calculation basis
IFC 2015 Section 3206.2	Extent and Type of Protection provisions	Limited area protection option
IFC 2015 Section 3206.2	High Hazard commodity classification	Tires classified as Group A plastic
NFPA 13 18.4(a) Exception #5	Miscellaneous storage (max 12' height, 0.6/5000 density)	Does not apply to carousels

Solution: Two-Part Protection Scheme

The most viable approach combines fire-resistive separation with appropriate sprinkler selection, creating an engineered solution that addresses both code compliance and practical water supply constraints.

Part 1: Fire Area Separation

Implement the Extent and Type of Protection provision per IFC Section 3206.2:

1. Isolate the tire carousel area with 1-hour fire-resistive rated construction
2. Install 45-minute fire-rated door assemblies at all openings
3. Equip doors with magnetic door holders releasing upon sprinkler waterflow
4. Document the isolated fire area in permit documentation

This approach limits the hazard extent, potentially allowing reduced design area calculations while maintaining code compliance.

Part 2: Sprinkler Selection

Two viable sprinkler approaches exist for tire carousel protection:

System Type	Sprinkler Rating	Pressure	Hose Demand	Notes
ESFR (Early Suppression Fast Response)	K25.2	15 PSI minimum	250 GPM	Per NFPA 13 Table 18.4(d)
Standard Pendant	K25.2	Varies by calc	250 GPM	Calculate based on room count or Table 18.4(d)
Standard Pendant	K11.2-K17.0	Varies by calc	250 GPM	Use smaller number of sprinklers from Table

FM Global Consideration

FM Global Data Sheet 8-3 on Group A Plastic carousel storage recommends additional protective measures:

• Install waterflow switches connected to carousel control systems
• Implement fire detection systems (heat or smoke detection)
• Configure detection to automatically stop carousel rotation upon fire alarm
• Prevents spread of burning tires throughout the facility

This active intervention approach reduces the likelihood of a full Involvement event and supports the argument for reduced water supply requirements.

Hydraulic Design Considerations

When designing the sprinkler system for tire carousel areas, calculate demand using the lesser of:

• The number of sprinklers specified by NFPA 13 Table 18.4(d) for the hazard classification
• The number of sprinklers located within the isolated fire area

This "smaller room" calculation method can significantly reduce the design area, particularly for smaller carousel installations where the fire-rated room contains fewer than the table-required number of sprinklers.

Water Supply Infrastructure

If the two-part scheme approach is rejected by the Authority Having Jurisdiction (AHJ), prepare for substantial infrastructure requirements:

Component	Typical Requirement	Typical Cost Impact
Fire Pump	2000 GPM @ 100 PSI	$40,000 - $80,000
Primary Feed Main	10" minimum	$15,000 - $30,000 per 100 lineal ft
Bulk Mains	10" minimum	$8,000 - $15,000 per 100 lineal ft
Water Tank/Reservoir	Minimum 3,000 gallons	$25,000 - $50,000
Jockey Pump	10-25 GPM maintenance	$3,000 - $8,000

Verification Steps

1. Confirm tire carousel height exceeds 12 feet (excludes miscellaneous storage exception)
2. Obtain written approval from AHJ for the two-part protection scheme
3. Verify fire-rated construction assembly listings (1-hour rating documentation)
4. Confirm door holder release on waterflow (not general fire alarm)
5. Document sprinkler selection with hydraulic calculations per NFPA 13
6. Submit plan review documentation including isolation boundaries
7. Coordinate with FM Global if facility is insured under FM Global

Conclusion

Tire carousel fire protection design presents a genuine conflict between code-prescribed minimum water demands and practical engineering judgment. While NFPA 13 Section 23.4.4.2.4 technically mandates 3000 GPM for high hazard tire storage, the Extent and Type of Protection provisions in the IFC, combined with ESFR sprinkler technology, provide a defensible alternative that better matches protection requirements to actual hazard characteristics. Engage early with the AHJ to establish acceptance criteria for the two-part scheme. Document the engineering rationale thoroughly and ensure all fire-rated assemblies are properly listed and installed. For FM Global-insured properties, coordinate additional detection and carousel shutdown requirements.

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