If the area in which you are placing the curtains contains a sprinkler system, the curtain must not obstruct the sprinkler and thus must have a minimum of 18" of exposed mesh. This is a reference to Refers to section A.13 of NFPA 1 (which is an excerpt from the 2013 edition of NFPA 13: Installation of Sprinkler Systems). The code establishes that "for the proper operation of sprinkler systems, cubicle curtains and sprinkler locations need to be coordinated. Improperly designed systems might obstruct the sprinkler spray from reaching the fire or might shield the heat from the sprinkler. Many options are available to the designer including, but not limited to, hanging the cubicle curtains 18" Below the sprinkler deflector using 1/2" diagonal mesh or a 70 percent open weave top panel that extends 18" below the sprinkler deflector; or designing the system to have to have a horizontal and minimum vertical distance that meets the requirements of NFPA 13".
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