Whenever we decide to adopt a new vibrant housing idea floating in the market, especially in the sense of repurposing or recycling, the first sensible question that should pop in our mind is, Is it safe?
If briefly answered, there are certain health and safety challenges in making a shipping container livable, but with all the technology and products present in today’s world, those could be overcome at a cost. Shipping containers can be made Safe and livable with a few careful considerations and steps discussed further in this article.
Let’s dive into these safety aspects of Shipping Containers homes in detail.
- Life span of the Container home
- Presence of chemicals
- Hurricane and earthquake resilience
- Theft security
- Fire Safety
- Security from Rodents and insects
At the end of this article, you shall find a convenient checklist to make your process of creating a safe shipping container home easier.
Life Span of the Container (Home)
When deciding to buy a shipping container home, the first thing to consider is, “how long is investing in a shipping container home worth it for?” The average life of a shipping container home is 25-30 years. The word ‘average’ is the key here, as different climates affect the metal differently. For e.g., harsh weather conditions and constant exposure to the sun’s UV rays may cause the metal to corrode faster than expected. Although these containers are made of Corten steel, it does not prevent corrosion, just delays the process.
However, these homes can thrive and live their full life if maintained attentively and regularly. As these are metal boxes, maintenance primarily includes basic things like timely repainting of the exposed area, shading, proper insulation (to prevent condensation) and checking for rust and corrosion at intervals.
Presence of Chemicals
As shipping containers are prepared to withstand constant exposure to salt and extreme humidity, they are treated using chemicals. This section shall clear all doubts regarding any hazard to your living environment due to that.
he floor of shipping containers has to withstand salt, humidity and prevent insects, pests or molds throughout its long travels of the sea. Therefore, it is treated using certain chemicals and pesticides. The details of these treatments are generally mentioned on the CSC (convention for safe containers) plates on the left door of the container. These chemicals mostly include basileum, talileum 400, and radaleum. However, health and regulatory organizations have agreed that these are harmless to mammals and harms insects only. MBI and NPSA white paper also notes that basilieum affects insect metabolism but is “virtually non-toxic to mammals.”
On the other hand, Talileum 400 can be toxic to mammals, but only if ingested in large, concentrated amounts, which is unlikely as the floors are infused with only a small amount. In addition, Talileum and Radaleum have low vapor pressure, meaning they will not readily diffuse into the air.
Hence, the original chemicals used to treat the flooring are NOT a concern regarding a livable environment. If still in doubt, it can be covered with non-breathable sealants or underlayment and then tiled over.
As the shipping container is not designed to live in and specifically designed to withstand the saltwater and moisture, the paint used for the container might contain harmful chemicals such as phosphorus and chromate and not be safe to live within. Although there is no prominent proof or study to prove its negative effect, its effect on the living environment is debatable at best. These chemicals can cause serious health problems when spilt, inhaled or touched.
To rectify the issue, sandblasting to remove the entire paint is the safest option. Or, the container can also be painted with a non-breathable sealant and then painted over.
However, it is vital to wear proper safety equipment and masks while carrying out these processes, as both these activities could put you in touch with those chemicals and their harmful effects.
Depending on the things transported in the container throughout its life, it could cause a potentially toxic environment to live in. For instance, if it was used to transport any harmful chemicals or pesticides anytime in its life, it might have spilt and absorbed in the container’s floor (being the most porous element of its structure). In such a situation, getting rid of minute fumes or harmful effects of the absorbed chemicals is an unsafe challenge. Even deep cleaning might not be able to get rid of those.
Ignoring the possibility or any misinformation regarding this can lead to hazardous living conditions and life-threatening health issues, even without one realizing it until it’s too late.
To confirm if this issue persists, one can contact the port it was last on and check its contents based on the unique container number present on the CSC plate on the left door of the container.
There are two possible ways to address this issue.
- Replacing the floor of the container
- Covering the floor with a non-breathable flooring underlayment. This will prevent the harmful vapour from chemicals spilt on the container’s wooden floor from penetrating the surface. Then, the floor can be tiled for maximum safety.
There are ways that can be used to rectify the issue. However, to be on the safer side buying a new shipping container could be a better option depending on your budget and circumstances. Good news is, when ordering a new container from the manufacturer directly, you can instruct the manufacturer to use safe livable certified paints and treatments, thus avoid any of these issue in the first place.
Note: Buying a new shipping container is not the greenest option, as it contradicts the initial idea of repurposing discarded shipping containers.
Hurricane and earthquake resistance
Another reason shipping container homes have gained such popularity worldwide is its heavy, structurally sound body, designed to withstand the wrath of sea storms. It is exceptionally stable and hurricane resistant. Therefore, they make a suitable module for emergency housing and refugee units as they can stand temporarily on their own without the fear of tumbling or getting blown off, even in high scale hurricanes and winds.
Strength of Shipping Containers
These containers are originally manufactured and tested according to the ISO standards before even beginning their life as a container. They go through an intense rigidity test that applies a shear force of 150 kN, or 33,721 lb, on the top edge of the container. This force can be translated into the windspeed to gauge how much it can withstand. According to the rigidity test, a shipping container without any voids or modifications can withstand wind speeds of about 180 mph without wavering. Also, the sturdy steel body absorbs more energy than wood; therefore, it stands significantly better in an earthquake or a storm.
The test and limits above are essentially for a closed shipping container. The type and number of modifications made in the process of making it a home, can affect these results accordingly. The size of the openings, and type of doors and windows and additional structural members used might reduce the number and make it weaker.
- Doors and Windows: It is advisable that if you live in a disaster-prone area, you must install impact windows. Impact windows might significantly reduce the loss of strength compared to regular windows, which are bound to collapse in a disaster.
- Structure: The structural system of a shipping container homes is concentrated at the four corners (As they are meant for stacking). The strength in the walls is due to the corrugations. Therefore, the size of the openings cut, can significantly affect the strength of the container. If the doors and windows are large, then the wall would require additional wooden or steel bracings.
Similarly, the roof of the shipping container is also vulnerable. It is advisable to build load bearing walls within the home, or to add a secondary roof to avoid sagging and weakening of the roof due to snow or any other load.
Are the homes resilient enough?
Now that we know that shipping containers themselves are pre-tested and are very strong. To confirm that the houses after modifications shall also be able to withstand these disasters, let’s look at the example of Puerto Rico. After hurricane Maria, when things were devastated in Puerto Rico, anchored shipping container units became a lifesaving solution for their hurricane-prone area. CNN reported that many people there now fearlessly own anchored shipping container homes that can survive both hurricanes and earthquakes up to 175 miles per hour.
However, Bob’s container company rightly warns, even though the living envelope can survive these conditions, it might still leave you stranded with no services. It all depends on how these services were installed and placed within or about the house.
The first thing to know is that even though shipping containers are strong, they are mostly stored in a locked facility or garage when not on a ship. So, yes, they are strong and not easy to break into if its steel door is securely locked; however, they are not specially designed to be protected from theft or vandalism. When you cut voids for windows and doors and convert it into your home located in an open locality, it becomes only as safe as any other house.
You will need extra active or passive security measures such as cameras, grills etc. to strengthen its safety.
Unfortunately, the strength and composition of shipping container doesn’t work to an advantage in case of fire. The original design of shipping containers is such that its sidewalls are designed to withstand shifting loads up to 60% of the permissible load, and the end wall and doors are designed to withstand 40% of the permissible load. Therefore, in case of fire, these containers allow a build-up of internal pressure to the point where it fails catastrophically.
But this is the case with a closed shipping container. When you open it up and install doors and windows, the possibility of pressure build-up minimizes significantly, as other materials with relatively less strengths come into play.
However, it is more crucial to ensure proper cross ventilation and exit points for air and pressure in a shipping container home due to its composition and strength.
Security from Rodents and insects
Again, Shipping containers are originally watertight and are evidently protected from termites, insects or rodents. However, it is imperative to inspect the container (especially if used) for any tiny holes, corrosion or damage, that could weaken its sealed quality.
Checklist for ensuring a safe and secure container home
Now, that you are aware of the issues, to ensure that your shipping container home is safe, tick off all the points on this checklist:
- Do not touch the container with bare hands unless sure of the absence of harmful chemicals.
- Check for any holes or corrosion on the shipping container
- Read its CSC plate, found on the left door of the container, contact the manufacturer, and find out the paint and transport details based on the number.
- Ensure that it was not used to transport any toxic chemicals. If so, then take necessary measures to get rid of their influence.
- Engage in careful planning and layout design regarding openings and windows.
- Select the doors and windows based on your location and its probability of natural disasters.
- Employ active and passive security measures to prevent theft and vandalism based on your location and use of the home.
Overall, A shipping container offers a structurally safe envelope. However, it needs some attention and solutions to get rid of chemical influence if any and make it safe for the long-term health of the inhabitants.