Max Head Coverage in attic / concealed space

[doingwhat]

a 1 story building with a 2x10 wood trusses and the roof pitch is less than 4:12

Is the space between the wood trusses and the suspended ceiling an attic or concealed space? What is the difference between attic and concealed space?
So in this case, what is the maximum coverage per head in this space? My plan checker is telling me the maximum coverage is 120 SF. However, I think this is only applied for slope roof that has a pitch 4:12 or greater.

 

[cdafd]

Can a person get into this space?

Which brand and model sprinkler are you using??

I am thinking you can have a concealed space in an attic, but not an attic in a concealed space??

 

[TravisMack]

Either way, you have a space with combustible construction with framing members less than 36" on center. You have to go with 130 sq ft max. Since pitch is <4:12 then you don't need to meet that criteria. Is the roof flat (≤2:12)? Is there less than 36" clear? If so, you are looking at specially listed sprinklers like the Tyco CC3 or similar.

Look at TAbLe 8.6.2.2.1(a) in the 2016 edition for clarification.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, a Ferguson Enterprise

http://www.mfpdesign.com