What Chemicals Need to Be Removed From Shipping Containers Before Construction?

Shipping containers are designed to endure a life at sea. Since most cargo ships have issues with rodents that live as stowaways aboard the ship, the wooden flooring in shipping containers is usually heavily treated with pesticides to deter these unwanted guests. Steel walls and roofs of shipping containers usually contain paints incorporating heavy metals such as phosphorus and chromate . These chemicals help protect the steel from the steady spray of saltwater, which can corrode the steel containers. One recent study showed that when shipping containers arrive in a harbor, up to 20% of these containers contain volatile toxic substances that are substantially higher than the established exposure limit values and that these volatile, off-gassing chemicals can lead to serious health risks for dock workers, customs inspectors, and others. The types of gasses accumulating inside these airtight containers also depend on what is being shipped. However, it is common for dangerous chemicals such as formaldehyde, styrene, benzene, or toluene . When transforming a shipping container into a livable home, one of the first tasks should be ripping out the pesticide-laced flooring and taking measures to cover or encapsulate the toxic paints. Trying to remove the toxic paint will most likely lead to more off-gassing and dangerous dust that poses serious health risks when inhaled. Instead, using a non-toxic sealing primer will help encapsulate the chemicals and block the off-gassing of hazardous, volatile organic compounds.

What Are A Few Tips to Make Your Recycled Shipping Container Home More Sustainable?

Suppose you have chosen a “retired” and well-used shipping container and done the work to remove the potentially dangerous, toxic chemicals. In that case, you can still do a few things to maximize the sustainability of your home. Steel conducts heat efficiently, meaning that your shipping container home will need to be more heavily insulated than a traditional stick-built or brick home in most climates. If your shipping container home isn’t well-insulated (including the floor and the roof), the energetic cost to maintain the home comfortable will be high. While most contractors who specialize in shipping container construction use spray foam insulation because it adheres well to the containers' irregular shape, almost all spray insulation is made from polyurethane, leading to health problems, asthma, lung problems, and respiratory irregularities . These sprays often also have a high Global Warming Potential . One natural way to insulate a shipping container home is through straw bales to the home's exterior. Straw bale construction has existed for centuries and is a great way to reuse the leftover products of grain agriculture that are sometimes burned or left to rot. Straw bales are some of the best building materials for insulation, with R-values up to R-35 . To add straw bales to the exterior of your home, you will need to build a small stem wall to keep the straw bales free from ground moisture, which could cause rotting and mold issues. You need to plaster the straw bales with cement and lime stucco to further protect the bales from accumulating moisture. Shipping container homes will also need some roof and roof insulation. Adding a green or living roof is one way to kill two birds with one stone. The steel roofing of a shipping container offers a perfect “substrate” to build a living roof . You will most likely need to add some steel stud reinforcements to the roof, but the steel itself will offer an impermeable layer or at least a roofing layer that is more waterproof than the traditional 2x4s and plywood. On top of the reinforced steel roof, you will need to add a small layer of rigid insulation slightly pitched to help in water runoff. A waterproof membrane such as a pond liner then covers the insulation. On top of the pond liner is placed a growing medium encased by steel bars to keep the soil on your roof from sliding off during heavy rain. Once your growing medium is in place, you can plant flowers, turf, or other types of plants (even vegetables) on top of your home. The thick growing medium is not only beautiful but also offers a thick layer of insulation to keep your shipping container home warm.