High Piled Storage of Hay Bales?

[arion]

Hi,

We reviewed a metal framed building that stores 4'Wx8'Lx3'H bales of hay in grouped stacks, and they are looking to stack upward. The two high piled storage areas have a CMDA design density/area of .35/2,940 (Area #1) and a CMSA design of 25 heads @ 25 PSI (Area #2).

The 2013 California Fire Code classifies bales of hay as "Combustible Fibers". In all other commodity classifications I've read, I cannot find anywhere how it is classified in terms of something I can compare to see if the existing ceiling sprinkler system is adequate. What code/standard should be used to determine the sprinkler criteria necessary for warehouses of baled hay/combustible fibers?

I found NFPA Table 20.4.2.1 for bales cotton storage, but I do not think this is comparable enough, because many references to baled cotton say that it is excluded from the definition of Combustible Fibers.

Thanks

 

[stookeyfpe]

What section from the California Fire Code are you quoting from?

 

[arion]

CFC Chapter 2 definition: COMBUSTIBLE FIBERS. Readily ignitable and free-burning materials in a fibrous or shredded form, such as cocoa fiber, cloth, cotton, excelsior, hay, hemp, henequen, istle, jute, kapok, oakum, rags, sisal, Spanish moss, straw, tow, wastepaper, certain synthetic fibers or other like materials. This definition does not include densely packed baled cotton.

 

[LCREP]

No matter what type of sprinkler system you install do not expect the fire to be controlled by the sprinkler system. The only way the fire is going to be extinguished is to pull each bale out and wet it down. I say this after fighting many barn fires, no matter how much water you put on a bale it is not going out. Deep seated fires are real difficult to extinguish. With that said go with baled cotton protection. Or look at the definition of extra hazard Grp 2, shielded fires, see below. Highly unlikely anyone has done any testing on hay storage to determine protection criteria. Higher a fire protection engineer to figure it out is yet another option.

5.4.2* Extra Hazard (Group 2). Extra hazard (Group 2) occupancies shall be defined as occupancies or portions of other occupancies with moderate to substantial amounts of flammable or combustible liquids or occupancies where shielding of combustibles is extensive.

 

[skdesigner]

FM DS 8-7 contains recommendations for the protection of baled fiber storage. The datasheet indicates a density of 0.16 gpm/sf / 6,000 sf.

 

[arion]

LCREP, I am waiting for a response from my FPE on this as well, thank you for the insight.

skdesigner, thanks for the direction as well on FMDS 8-7. I wish it included hay just to have a clear answer, but this is great. With a combination of FMDS 8-7 and other supporting materials, we can close in on a suitable protection criteria.

Any other ideas or reference materials?

Thanks very much

 

[Duwe6]

LCREP is exactly right, sprinklers will keep you from having a major fire, but they CANNOT extinguish a hay fire. The firefighters will have to pull out each and every burning/smouldering bale and tear it appart to put it out. Thus, "Real World" it doesn't much matter how many sprinkler heads there are, as long as there is coverage of the whole pile.

Further, safe storage of hay requires on-site inspections. The storage facility needs to be walked daily, sniffing for smouldering hay. On cool, damp mornings the tops of the stacks need to be walked/crawled looking for warm spots. If hay is put up with a moisture content much over 10%, it may autoignite due to biological action. Only store dry hay indoors.