Floor Mounted Obstructions - Extra Hazard

[Haldorson]

In NFPA 13 (2010) Figure 8.6.5.2.2 describes floor mounted obstructions in LH occupancies only. Is there analogous rules for OH or EH occupancies with regards to floor mounted obstructions?

 

[skdesigner]

Short answer, no. Note that 8.6.5.2.2 ends at 18" below the deflector. Not coincidentally, this is where the obstruction rules for standard spray heads change. NFPA 13 2010 is giving a spacing credit for light hazard occupancies that doesn't extend to ordinary and extra hazard. Therefore, if the obstruction was 18" or closer to the deflector, you would treat it as a wall and space accordingly. If it was greater than 18" below the deflector, you would apply NFPA 13-2010 8.5.5.3. If your floor mounted obstruction doesn't fall into one of the "sprinkler required below" categories, then go on your merry way and space heads as if it didn't exist.

 

[cdafd]

the commentary refers to this testing, and says since there was not testing in oh or eh

http://fire.nist.gov/bfrlpubs/fire80/PDF/f80013.pdf

I think you still have to assure you get water where it is suppose to go, and does 8.6.5.3 pick up oh???