Obstructed Construction W/ Multiple Beam Sizes

[Jondoeiowa]

Under NFPA 13 2010 8.6.4.1.2 - 1 "Installed with deflectors within horizontal planes of 1 in. to 6 in. below the structural members and a maximum distance of 22 in. below ceiling/roof deck."

I have an exposed deck with 30" beams down to 8" beams. I am using any beam larger than 24" as an obstruction and all beams 18" or less allowing Obstructed construction. But when placing my heads for Elevation, I have 18" beams next to 8" beams, next to 12" beams so the 1" to 6" part of the rule has me ask.

Do I place the head 1" to 6" below the lowest beam, or do I sprig the heads and adjust each head accordingly. If so when between a 8" beam and a 18" beam which do I measure the 1" to 6" from?

 

[cdafd]

would need to see a drawing, showing the beams, head placement, and dimensions

 

[Jondoeiowa]

Attached is a PDF copy of the 2 areas in question.