Aircraft Hanger, NFPA 409 and steeply pitched roofs

[SprinklerDesigner2]

I am sure the answer is yes but humor me.

I have an aircraft hanger designed to a density of .17/5000 per NFPA #409 7.2.5

7.2.5 The design density from sprinkler systems shall be a minimum of 6.9 L/min/m2 (0.17 gpm of water per ft2) over any 464.5-m2 (5000-ft2) area, including the hydraulically most demanding area as defined in NFPA 13, Standard for the Installation of Sprinkler Systems.

NFPA #13 A.5.4.1

A.5.4.1 Extra hazard occupancies (Group 1) include occupancies having uses and conditions similar to the following:
Aircraft hangars (except as governed by NFPA 409, Standard on Aircraft Hangars)

The roof pitch exceeds 2 in 12.

From NFPA #13 11.2.3.2.4

11.2.3.2.4 Sloped Ceilings in Non-Storage Applications. The system area of operation shall be increased by 30 percent without revising the density when the following types of sprinklers are used on sloped ceilings with a pitch exceeding one in six (a rise of two units in a run of 12 units, a roof slope of 16.7 percent) in non-storage applications:

Seeing how the appendix of 13 defines aircraft hangers as Extra Hazard we can not claim it's "storage". Since it isn't storage we have to increase the 5,000 sq. ft. area of operation to 6,500 sq. ft..

Am I right?

 

[stookeyfpe]

I would agree with your interpretation.