The Answer is Six Feet
(well it depends)
The International Building Code regulates combustible storage in section 413 of the 2006 edition. The section requires that high piled stock or storage in any occupancy group shall comply with the International Fire Code. The section also provides clarification on combustible storage in under-floor and concealed spaces (see section 413.2 for more clarification). Chapter 23 provides guidance for protection of life from hazards associated from high pile storage.
As the user traverses codes to the IFC 2006, you will find a detailed chapter 23 which provides requirements on the configuration, height of storage and additional requirements which are triggered based on the area of storage. The “other requirements” may include an automatic sprinkler system, automatic detection system, smoke/heat venting or additional exterior doors.
“High Piled Storage” is defined in IFC 2302 as:
“Storage of combustible materials in closely packed piles or combustible materials on pallets, in racks or on shelves where the top of storage is greater than 12 feet (3658 mm) in height.” When required by the fire code official, high-piled combustible storage also includes certain high-hazard commodities, such as rubber tires, Group A plastics, flammable liquids, idle pallets and similar commodities, where the top of storage is greater than 6 feet (1829 mm) in height.
This definition provides the basis for the application of the chapter. Prior to conducting inspections on these occupancies, the design professional shall address the storage during the plan review process. The design professional shall include an application for permit (IFC 105.6) and a proper design submittal, which, at a minimum, must include:
- Floor plan of the building showing locations and dimensions of high-piled storage areas.
- Usable storage height for each storage area.
- Number of tiers within each rack, if applicable.
- Commodity clearance between top of storage and the sprinkler deflector for each storage arrangement.
- Aisle dimensions between each storage array.
- Maximum pile volume for each storage array.
- Location and classification of commodities in accordance with Section 2303.
- Location of commodities which are banded or encapsulated.
- Location of required fire department access doors.
- Type of fire suppression and fire detection systems.
- Location of valves controlling the water supply of ceiling and in-rack sprinklers.
- Type, location and specifications of smoke removal and curtain board systems.
- Dimension and location of transverse and longitudinal flue spaces.
- Additional information regarding required design features, commodities, storage arrangement and fire protection features within the high-piled storage area shall be provided at the time of submittal
The design professional shall identify the requirements of chapter 23 on the submittal and include special attention to section 2306. During the site plan review, it is a good idea that a preliminary review of this section be performed. If the building does not include an automatic sprinkler system based on the requirements found in chapter 9 of the IBC or due to height and area calculations, the storage configuration must be evaluated. During building plan review the reviewer must ensure these requirements are identified in the submittal.