Steel Shipping Containers Inherent Fire Rating

I have client who wants to use the steel shipping containers ( 20 foot/ 40 foot ) as a commercial storage business

Do they have any inherent fire rating? ( a building Act fire report is of course required in the normal manner)

Thijs Drupsteen

Being steel they are going to have an integrity rating but no insulation rating.


Steel shipping containers have ~2mm thick walls and are very carefully designed to provide structural support with the minimum of material and use high tensile steel to get strength without weight. You will have no insulation rating as it is thin steel, and almost no structural rating. Various Fire Brigades use shipping containers as training rooms - fill it up with fuel and light it up, then attack the fire. I assume the NZ Fire Service does the same. This is only a single container on the ground, not a stack being supported by the containers below.

Some full scale fire testing was done for the marine industry in 1976 - see “fire performance of intermodal shipping containers” by Randell Eberly (US Coast Guard report CG-D-62-77, NIST 1977). This used wood cribs inside sealed and closed containers and also an external pool fire. There was no heat release rate data measured… The sealed containers had little damage as they were ventilation limited. This would not apply to a storage unit where doors may not be tight fitting and are likely to be open as people load and unload them
Given this was for looking at fire fighting and is now 40 years old, I would hesitate to use this as a source to justify no fire rating.
In the past, I have used the Gib universal wall and ceiling system to protect the container and container structure from an internal fire. Detailing junctions for continuity where required (e.g down the ground - these were on piles) as I recall was a sod of a job due to the corrugations, cutouts and details such as the system of a locking containers together

I have completed a couple of these recently (single storey application) - and proposed to install gib fire rated walls to the inside face where the containers are within a distance of the boundary, based on C/VM2 Table A2*.
Suggest you also refer to determinations:
2011/104 & 2014/30
I have employed a similar reference to Geoff regarding NZFS using containers many times over for firefighting training without failure, and the “live burns” do demonstrate how well a container is ventilation controlled even after numerous uses.
Containers are designed for sea going conditions with weathered steel (non-combustible cladding) and when single storeyed are inherantly stable especially when placed side-by-side.

Further to this thread, I came across this paper whcih has some fire testing. Gets pretty toasty inside with some of the floor removed as you would expect.
[](http://Fire Investigation in a Container - Moctar 2010)