Building Separation

[Jhale]

2018 IBC/2018 IFC
I have a new building that is proposed that is F1 at 15000 sq ft. main floor plus additional 3750 sq ft that is S-1. They were told they would need sprinklers initially. They decided to separate the main portion of the building with a 3-hour fire wall to reduce the total area of the F-1 occupancy to avoid placing automatic sprinklers. The reduced area is 11500 square feet. My question is would the S-1 area and the remaining part of the F-1 building which totals 15250 square feet still need to have automatic sprinklers (unless they chose to separate the S-1 area). Any guidance would be appreciated on this area. Thank you.

 

[steveray]

In theory....no...I believe the max is both 12000 ft fire areas for sprinklers unless you are doing something "special" in the S1 or F1....

 

[MADrkTEK]

Could you clarify your SF numbers?
F1: 15,000 SF
S1: 3,750 SF
total: 18,750 SF?
divided up into two buildings with a 3 hour fire wall:
Building one: F1 fire area: 11,500 SF
Building two: F1/S1 fire area: 7,250 SF? I’m not following where the 15,250 SF value comes from….

anyways, if any of your individual F1 or S1 Fire areas exceed 12,000 SF then you will need sprinklers. If you exceed 24,000 SF of either F1 or S1 aggregate fire areas in a Building, you will need sprinklers.

even though table 508.4 indicates that S1 and F1 use classification are not required to be separated, chapter 9 still establishes maximum thresholds for how large fire areas containing eithe F1 or S1 uses can be (12,000 SF individually, 24,000 SF aggregate each type). So I believe that if your remaining space is 15,250 SF and contains F1 and S1 uses that are not divided up further with fire barriers, the yes, you need sprinklers.