Does Wood Plywood Qualify as Encapsulation?

11/7/2023

We are doing a design for high-piled storage of Class I-IV commodities in a palletized arrangement. Storage is 15'-6" high.

Would this storage (image below) also count/qualify as "encapsulated" under NFPA 13 (2013 Edition)?

The client is a remediation company that uses heavy plywood crates to temporarily store items for their clients (which are common household items).

Section 3.9.1.12 includes "a combustible package" as a method of encapsulation, but annex A.3.9.1.12 says "The term encapsulated does not apply to plastic-enclosed products or packages inside a large, non-plastic, enclosed container.".

Does a heavy plywood crate count as encapsulation, or not?

This matters because at 15.5 feet in height I would have to use the flow densities from 14.2.5 instead of the reduced ones from 14.2.4 if it does.

Thanks very much for your help.

Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

9 Comments

Pete H

11/7/2023 06:56:00 am

It doesn't count as encapsulation. From NFPA 13 (2013 edition)

3.9.1.12 Encapsulation - A method of packaging that either consists of a plastic sheet completely enclosing the sides and top of a pallet load containing a combustible commodity, a combustible package, or a group of combustible packages [you don't have this as the combustible plywood container is outside of the plastic and part of the pallet load] or consists of combustible commodities individually wrapped in plastic sheeting and stored exposed in a pallet load [your stuff isn't stored exposed, it's inside a plywood box.]

A.3.9.1.12 Encapsulation - Totally noncombustible commodities [you don't have this] on wood pallets enclosed only by a plastic sheet as described are not covered under this definition. Banding (i,.e,. stretch-wrapping around the sides only of a pallet load) is not considered to be encapsulation. Where there are holes or voids in the plastic or waterproof cover on the top of the carton that exceed more than half the area of the cover, the term encapsulated does not apply. The term encapsulated does not apply to plastic-enclosed products or packages inside a large, nonplastic, enclosed container [this is what you may have, but the term encapsulated does not apply].

11/7/2023 08:15:29 am

This is the way I read it as well. The "combustible packaging" refers to what is being encapsulated, and does not describe another type of encapsulation.

Alex

11/7/2023 08:31:53 am

I agree with Pete here! Not much more to add.

Jesse

11/7/2023 08:18:17 am

That's not encapsulated. Encapsulation typically uses a polystyrene or similar wrap on 5 sides of the load.

I had a warehouse once that used similar in a high piled (palletized) storage array. I wanna say we treated it as a Class III Commodity.

Nick

11/7/2023 08:29:39 am

I would be careful of following the commodity classifications found in chapter 5.6 of NFPA 13. See Table A.5.6 for examples of commodities not addressed by NFPA 13. It specifically lists "Storage Container - Large container storage of household goods" as not being addressed which I believe is the exact condition you show here.

If that is the case, providing coverage for a class I-IV commodity would not cover this storage arrangement, regardless of "encapsulation" or not. This will probably require a performance based design or further research into other standards that have done testing for protection of these crates. I have to imagine there is a very specific reason why NFPA 13 directly states that their definition of commodities does not address this scenario.

Glenn Berger

11/7/2023 08:54:54 am

This is a classic case of utilizing the definitions from the standard being questioned.

NFPA 13 definitions apply to this scenario and your photo does not meet the definition of encapsulated.

Casey Milhorn

11/7/2023 09:17:27 am

Nick is spot on. This storage arrangement is becoming very popular with the self storage/moving companies. The customer can pack whatever they want in there while it sits in their driveway, close the door on it, have it picked up and stored two or three containers high in a warehouse that many times was never designed for this. I did a little research a few months back and I could not find any testing that has been done on this type of storage (I didn't spend a whole lot of time on it either). It definitely should be performance based design with someone experienced with this type of storage. It could test out very well in fire testing and be protected with OH2, then again it might need 2000gpm+ of ESFR protection, or not even allowed at all in certain arrangements. I would imagine the performance based spec would also dictate spacing of containers, flue spaces, aisles, max# of containers that can be stacked, clearance to roof sprinklers, etc.... just my two cents

11/7/2023 09:29:15 am

Thanks everyone! I was leaning that way too but I wanted a few extra sets of eyes on it first.

Much appreciated. Gotta love this community. :-)

Dan Wilder

11/7/2023 11:16:02 am

Encapsulation - I look at it as the ability to not allow prewetting of the pallet load (sides AND top) mostly with the use of plastic wrapping.

Not sure how the initial Class IV designation would work as furniture (with cushions) is a Group A? Maybe getting there via modifiers down the line but shielding should also be a criteria in the evaluation.

This storage arrangement would fall outside NFPA 13's scope based on the picture and description IMO.

The last half of the article has some good insights:
https://www.sfpe.org/publications/fpemagazine/fpearchives/2006q1/2006q12

Does Wood Plywood Qualify as Encapsulation?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES