8 Foot Height for Storage?

[jimnogood]

All,

Is there somewhere in NPFA 13 that states that if incidental storage is limited to 8 feet in a Light Hazard Occupancy, the design criteria can remain for LH, and not have to meet the criteria for Miscellaneous Storage (up to 12 feet)? Our senior guy seems to think that it is somewhere in 13, but not sure where. Any help would be appreciated. Thx.

 

[skdesigner]

Not sure if this is exactly what you're looking for, but:

NFPA 13 2010 20.6.1 Compact storage modules up to 8ft high storing commodities consisting of paper files, magazines, books, and similar documents in folders and miscellaneous supplies with no more than 5 percent plastics shall be permitted to be classified as light hazard.

 

[LCREP]

Nope see NFPA 13, 2010 definition of light hazard

5.2* Light Hazard Occupancies. Light hazard occupancies shall be defined as occupancies or portions of other occupancies where the quantity and/or combustibility of contents is low and fires with relatively low rates of heat release are expected.

Only exception is as noted above for compact storage and that is limited to 250 sq. ft. also the other exception is library stack rooms, see below what is in the Annex on this.

Note that it is not the committee’s intent to automatically
equate library bookshelves with ordinary hazard occupancies
or with library stacks. Typical library bookshelves of approximately 8 ft (2.4 m) in height, containing books stored vertically on end, held in place in close association with each other, with aisles wider than 30 in. (762 mm) can be considered to be light hazard occupancies. Similarly, library stack areas, which are more akin to shelf storage or record storage, as defined in NFPA 232, Standard for the Protection of Records, should be considered
to be ordinary hazard occupancies

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[pipesnpumps]

I can't recall anywhere this is spelled out. This is one of those grey areas of the code. "It depends".. on whomever you ask. How much is too much "storage" for LH? Good question, but the answer is subjective in my opinion, and ideally the answer would depend on the heat release rate potential, and what density is needed to achieve fire control for the configuration of the fuel package.

I always look for storage rooms and record storage areas to be OH. Paper or cardboard boxes are Class III commodities and require OH2. When there are walls in place, that makes it easy to demarcate.

Its when the "storage" is within and amongst the light hazard occupancy thats when it gets dicey. I would hang your hat on the same Appendix language that LCREF quoted (the statement about libraries being light hazard), but only if your are talking apples to apples and have solid shelves, etc.


Be sure you don't exceed any of the usual miscellaneous storage definitions:
1) storage height <12 ft, and
2) Incidental to another occupancy use group, and
3) Max. 10% of the area of the building or 4,000 sq ft of the sprinklered area, and
4) Max 1000 sq ft in each storage pile, with 25 ft separation between other storage areas.
This includes any form of storage including palletized, bin box, shelf, back to back shelf, and rack type storage.
Refer to NFPA 13 section 5.6.3 to determine commodity class.

Here is another good question: if a library building is 90% bookshelf storage, what chapter of NFPA 13 applies to those areas?

 

[stookeyfpe]

Jimnogood

The designer is correct in questioning this. In the 2010 edition of NFPA 13, miscellaneous storage requirements are found in Table 13.2.1. A Light Hazard discharge density is inadequate.

In all cases the minimum discharge density for higher heat release rate fuel packages is OH1.

Pipes and Pumps: If you're asking about High Density Storage Systems, we've discussed this before:

http://www.eng-tips.com/viewthread.cfm?qid=222446

Merry Christmas from Austin, TX.

 

[pipesnpumps]

Stookey, I think the fundamental question here is, what is required to be protected as miscellaneous storage?

Of course the safer answer is protect any size/type of storage as per misc storage reqt's.

Jimnogood didn't elaborate on what his "incidental storage" consists of. Let's take an example: in an engineering office let's say we have a square but open area (bull-pen) of 7-ft shelving setup for vendor catalogs and reference materials. Probably ok for light hazard.

Now let's increase the size, and make it three long rows of reference material setup like a library, with solid shelves. This is still ok for light hazard (see the above appendix info re libraries). But one could make the conservative argument this is miscellaneous storage.. however, this contradicts the guidance language in the appendix. Note if we were storing newspapers instead of books and binders 'placed closely together', as an AHJ I would say that must be misc storage and protected with OH2.

No let's say the long rows of shelving were of wire shelving and we were storing books and binders. I would say OH2 is required (misc storage of class III commodities), since the fire can more easily grow vertically due to the type of shelves.

As they say its all in the details.. Any office environment I've ever been in looks more like misc. storage than light hazard, except if you look up at the sprinklers.

 

[stookeyfpe]

PNP

I didn't visualize what you described in the original posting. I can see your arrangement and the various permutations one would need to consider.

The devil is in the details...

 

[chillylulu]

I agree with pipesnpumps, with the following caveat:

Occupancy is based on contents and sources of combustion.

Libraries have very little equipment, and are usually well maintained.

So, in a theoretical engineering office (at least most) the lack of housekeeping and organization might put you out of the normal light hazard occupancy.