18 Jun Shipping Container Floor Issues to Consider
The Story Behind the Wood
The wood floors constructed into shipping containers have become a hotly contested issue over the past several years. As people find more and more creative uses for retired shipping containers they are claiming a positive environmental impact for their recycling efforts. On the other side of the equation, many container floors are manufactured using tropical hardwood trees. While still a renewable resource, it takes fifty to sixty years to replace one of these trees that was cut down to make container floors out of.
A larger issue for consideration is the chemicals impregnated into the container floors during manufacture. Australia has very strict requirements for treating shipping container floors; they are treated with serious insecticides and fungicides to keep alien insects and rodents from hitching a ride into Australia. Wood preservatives containing a number of organochlorine insecticides, including aldrin, dieldrin, chlordane and lindane, that have been approved in Australia for treating timber used as structural components in cargo containers. Subsequently, manufactures treat all containers for the Australian standards, they determined it is impossible to separate the units for a single country out of the pool and risk the fines and sanctions possible if an unapproved container is caught entering Australia.
Studies were done on these floors and they determined that insecticides can be transferred on to the products sitting on the container floors. The physical pick-up of insecticide from the surface of the floor is considered to be the major source of contamination. The highest insecticide residue levels were found in flour samples which were stored on newly treated laminated sawn timber. Chemicals like these previously mentioned do dissipate greatly after a couple of years, so with special prepping, cleanup, and sealing using epoxy coatings the chemicals can be isolated. Experts concur, if the out-gassing of chemicals is inhibited by a barrier then there is virtually no risk. This is similar to lead paint hazards in the past which have been corrected in traditional houses.
If the data plate is still on the container, it will indicate the types of chemicals the floor was originally treated with. Obviously if the flooring was damaged and changed somewhere along the line the data plate won’t help you. Nor will you ever learn what was shipped in and or spilled on your container floor during its high seas career. If a container is to be used for any type of permanent habitation, like a section of a container house for instance, the prudent course of action is to remove the original flooring, have it properly disposed of and install new flooring. You’re looking at ten sheets of plywood in a 40’ container plus labor; if you’re going to live in or serve food out of a container then you should include these costs in your modification budget.