Hi everyone, it’s Scott Wallask, and I was just on the ASHE e-mail group talking about 18-inch clearance requirements for sprinklers in storage areas. The question of storage along walls seems to come up a lot.
As many of you know, there is an exception for perimeter walls that allows you to forgo the 18-inch clearance between the top of storage shelves and the bottom of sprinkler pendants as long as the perimeter storage isn’t directly below a sprinkler.
The NFPA reference isn’t in the Life Safety Code, though — it’s in NFPA 13, Installation of Sprinkler Systems. I’ll use the 1999 edition of NFPA 13 because it’s what The Joint Commission currently recognizes.
Under that edition, look at annex note A-5-6.6:
The 18-inch dimension is not intended to limit the height of shelving on a wall or shelving against a wall in accordance with 5-6.6. Where shelving is installed on a wall and is not directly below sprinklers, the shelves, including storage thereon, can extend above the level of a plane located 18 inches below ceiling sprinkler deflectors. Shelving, and any storage thereon, directly below the sprinklers cannot extend above a plane located 18 inches below the ceiling sprinkler deflectors.
Also, if you’re Joint Commission accredited, check out LS.02.01.35, EP 6, as this also mentions the perimeter exception. EP 6 notes section 5-184.108.40.206 as the reference in NFPA 13, which also talks about clearance below sprinklers but doesn’t directly mention wall storage.
The theory behind permitting wall storage to extend above the 18-inch plane is that the wall will already obstruct sprinkler spray discharge patterns, so shelving along a wall isn’t going to make that situation worse. In the center of a storage room, however, storage that is too close to a sprinkler pendant could indeed alter discharge patterns, thus the 18-inch clearance requirements.