Introduction
Storage is usually treated as an operational detail, something that the tenant sorts out once the lease has been signed, when it is really a design input. The types of materials a building can store, how high it can be piled, and how it must be laid out are all integral factors in determining the required life safety features when the building is being designed.
Problems arise when the use of a building changes and the storage changes with it. A new supplier, a different packaging material, or one more layer on a pile can move a building out of compliance with the Fire Code and out of the commodity classification the sprinkler system was designed around. In Ontario, this is not supposed to happen quietly, since Section 10 of the Building Code Act requires a permit when a change in the use would increase the hazard, even when no construction work is proposed. That step is the one that tends to get skipped, and without proper review, resolving the deficiencies between what the building was designed to store and what is actually being stored can become very costly. The sections below look at some of the storage provisions within the Ontario Fire Code and the impact on sprinkler design based on NFPA 13, 2019 edition, that can change based on the storage configurations within a building.
Fire Code
The Ontario Fire Code deals with how a building is used, maintained, and operated after it has been built and applies retroactively. The Fire Code looks at the building as it stands today, regardless of when it was constructed or what was approved at the time.
An important step when determining storage requirements is determining the types and quantities of storage materials. The same material can have different storage requirements depending on whether it is loose, bailed, bagged, or boxed. Based on the classification of the materials, the Fire Code determines additional fire and life safety features that may be required, such as ventilation, spill control and drainage systems, and maximum storage quantities within a fire compartment.
From there, the Fire Code provides the required layout and clearances. For example, in a sprinklered building, a single storage area is limited to 1000 m2 for indoor general storage of combustible solids and noncombustible solids with combustible packaging or storage aid. Where multiple storage areas are provided, they must be separated by aisles. Additionally, unobstructed access aisles are required to be maintained for exits, to fire department access panels, and to fire protection equipment. Overhead clearances must be maintained between sprinkler head deflectors and the top of any storage pile; where commodities can swell or expand by absorbing moisture, a clearance must be kept between the storage and the walls. These requirements can be easy to miss when a few extra bales are stacked on a pile that was already at its limit.
NFPA 13
Storage occupancies present a fundamentally different fire hazard than typical industrial occupancies classified as Light, Ordinary, or Extra Hazard under NFPA 13-19. However, storage protection is not determined solely by these occupancy hazard classifications and requires evaluation of factors such as the type of storage commodity and storage configuration.
NFPA 13-19 classifies commodities from Class I to IV and Group A plastics and provides dedicated storage protection criteria that consider several variables, such as commodity classification, storage arrangement, storage height, ceiling height, pallet and packaging materials, rack configuration, and sprinkler type. In general, higher commodity classifications represent a greater fire challenge and can require more demanding sprinkler protection. For example, a Class II commodity can consist of ceramic mugs packaged in multiple layers of combustible cardboard cartons and stored on wooden pallets. However, if the same mugs were packaged using packing peanuts, which are a Group A expanded plastic material, the commodity would most likely be classified as Group A expanded plastics, requiring more stringent sprinkler protection criteria. Plastics present unique challenges because they burn faster and release more heat than ordinary combustible materials. Expanded Group A plastics can present a severe fire challenge because of their combustible polymer content, low-density configuration, and rapid-fire growth characteristics; such materials would require more demanding sprinkler protection criteria than Class I–IV commodities.  Â
Another storage configuration addressed by NFPA 13-19 is the storage of mixed commodities. In most cases, mixed commodities must be protected in accordance with the requirements for the highest commodity classification and storage arrangement. However, the lower commodity classification may be used when specific requirements are met in accordance with Chapter 20 of NFPA 13-19. Another option is mixed commodity segregation, in which lower-hazard commodities are stored separately from higher-hazard commodities. The higher-hazard area must then be protected based on the applicable requirements.
In addition to classifying commodities from Class I to IV and Group A plastics, NFPA 13-19 defines some special commodities, including tire and roll paper storage, which have specific design requirements. These commodities can exhibit fire characteristics that are not adequately represented by the conventional Class I–IV or Group A plastic classifications and therefore require specific protection criteria.
NFPA-13 does not cover all storage commodities or arrangements. NFPA published NFPA 30 for combustible liquids, NFPA 30B for storage of aerosol products, NFPA 484 standard for combustible metals, and NFPA 855 standard for the installation of stationary energy storage systems. In some cases, other standards may be required by the Authority having Jurisdiction (AHJ).
Conclusion
Before a change of use or new tenancy, the proposed storage conditions should be reviewed against both the Ontario Fire Code and NFPA 13. Confirming the commodity, packaging, storage height, arrangement, and required approvals early helps ensure that the building layout, sprinkler protection, and water supply remain appropriate for the actual hazard. Aisles and clearances do not accomplish much if the sprinkler system above them was designed for a lighter hazard, and a correctly designed sprinkler system can lose its effectiveness if the storage below obstructs the sprinkler’s discharge pattern. Addressing these considerations at the planning stage can be more efficient and cost-effective than correcting deficiencies after the space is occupied.