What determines weather a glass wall needs a water curtain or not?
Is the wall required to be fire rated?
NFPA 13 does not specify an equivalent fire separation rating for water curtains. So not certain why one was being installed?
What you are referring to is not a "Water Curtain" it would seem.
Water Curtains are used for Atrium type separations as defined in the Building Code, using Standard Spray Sprinklers.
Other uses per NFPA 13 are for Vertical Openings, 8.15.4, or for Proscenium Openings on stages, 126.96.36.199
It appears what you are referring to is Glazing Protection.
A new section was added to the 2016 edition of NFPA 13 for this.
Please reference 8.15.26. Which requires listed type Window Sprinklers among other things.
As to what requires it, that is a function of the building code.
Sprinklers do not provide a rating, or a rating equivalency.
They provide protection in lieu of rating.
Matthew J. Willis, CWBSP
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