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 5-188.8.131.52 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.