In our line of work, we come across some real doozies when it comes to fire protection arrangements. One of the more common issues we come across is the obstruction of sprinkler heads. Since 1980 OSHA has required that we maintain our storage at least 18″ below any sprinkler head.
1910.159(c)(10) Sprinkler spacing. The employer shall assure that sprinklers are spaced to provide a maximum protection area per sprinkler, a minimum of interference to the discharge pattern by building or structural members or building contents and suitable sensitivity to possible fire hazards. The minimum vertical clearance between sprinklers and material below shall be 18 inches (45.7 cm).
But this is all changing now, as both NFPA 13 and the 2018 IFC permit storage to encroach on the 18″ rule as long as the shelving/storage is less than 30″ out from the wall. Here is their rationale…
NOTE: OSHA will most likely continue to enforce their 18″ rule! But if you get dinged with a citation, and you can show you’re complying with a more recent standard, the A.D. may have mercy on you.
In a sprinklered building, NFPA 13 Section 8.6.6.2.1 now allows the top of storage on shelving on a wall to extend above the plane at 18″ below the deflector. NFPA 13, Section 3.9.2.6 indicates that shelving, by definition, is 30 inches or less in depth. Based on these two sections, NFPA 13 stipulates that storage along the wall on shelves with a depth of 30 inches is not limited to the storage height of 18 inches below the deflector. The new exception in the IFC correlates with this allowance.
It is important to note that this allowance is located in Chapter 3 and is a general requirement applicable to general storage arrangements. These exceptions are not located in Chapter 32 for high-piled combustible storage, nor is this section referenced by Chapter 32. As indicated in Section 102.10 of the IFC, when there is a difference between a general requirement and specific requirement, the specific requirement will apply. Applying this concept, Section 315.3.1 will apply to general storage, but not to high-piled storage arrangements.