Since shipping containers are not originally designed to be a building product for homes, it is reasonable to ask if homes built with shipping containers safe to live in.
Safety measures need to be done before shipping containers are used as homes. Many have these inherent safety issues:
- Lead paint to protect the steel from the salty environment
- Toxic off-gases from pesticides in the floor
- Toxic off-gases from chemical cargo
- Structural damage during usages
Knowing about these hazards and how to deal with them is an important first step for shipping container home builders and owners. Let’s look at each of them below.
Hazard One: Lead Paint
Lead paint was banned for general consumer use 1978 by the United State Federal Government. Some state banned it earlier than that.
But, modern shipping containers can often have lead in the paint that was sprayed on them.
Keep in mind that shipping containers are designed to be used in very extreme environments at sea. Salty air and water can deteriorate metals very fast. Having lead in the paint can help protect the metal from being damaged while exposed to extreme environment.
If the container has lead paint on it, then the lead can become air borne when the painted surface is sanded to remove rusty areas or cut for new doors and windows.
If you own a shipping container that is to be used for a home and are wondering if a certain shipping container has lead in its paint, then ask the distributor or the manufacturer if it was painted with lead paint.
If there are no records available that says whether or not the paint has lead, then hire a lead paint inspector to test the paint for lead.
It is strongly advised to hire a certified lead paint specialist to test for evidence of lead in the shipping container. They can also advise how to deal with the lead if it discovered. Check your local directory for a specialist near you.
Three Methods to Deal with Lead Paint
Method One: Don’t Buy a Shipping Container with Lead Paint
The best solution for most shipping container home dwellers is to not buy a shipping container that has lead paint.
There are new and used shipping containers without lead paint available. They will cost a little more than ones that are known to have lead paint. But, you will have a piece of mind that this toxin will not be around your home.
Also, buying a shipping container without lead paint for a premium price will save you the money of trying to get rid of the lead paint or sealing it off.
Method Two: Remove the Lead Paint
The lead paint can be removed by a certified or licensed lead paint removal services. This can be costly and timely.
Some resources indicate that it will cost $8 to $15 per square foot of the home. So, if you are using a 40 foot shipping container, then it could cost anywhere between $2,500 to $5,000. Having a home built with multiple shipping containers will proportionally be more.
Removing the lead paint is a more permanent solution than the next remedy. It also will give a better sense of security especially if children are to live in the shipping container home.
Method Three: Encapsulate the Lead Paint
The lead paint could be encapsulated. Some call this method, “treating” the lead paint. That means the paint would be covered over by some other material, often a special paint that prohibits anyone to be in contact with the lead paint.
The surfaces to be covered must be clean, without cracks, and free from moisture and contaminates.
The air around the lead paint needs to have a specific humidity level and temperature before adding anything over the hazardous areas.
Another disadvantage to encapsulating the lead paint is that the new covering could peel off and expose the lead paint. Water leaks can also damage the encapsulates.
There would be a requirement of constant maintenance and monitoring to be sure that the lead paint is properly covered and out of any harm’s way.
Hazard Two: Pesticides
Pesticides are often sprayed onto the wooden plywood floor of shipping containers.
Check the tag on the shipping container door to see if it was fumigated. Or, check with the distributor or manufacturer to find out if pesticides were used.
Five Methods to Deal with Off-Gases from Pesticides
There are testing methods to determine of the shipping container has hazardous gases. But, some of the common methods are not fully reliable.
The testing procedure includes tubes placed into the container to absorb gases that will be studied and measured. One tube can only be tested for one type of gas. This adds to the difficulty of finding all the toxic gases that might be in the shipping container.
Method One: Buy Shipping Containers Without Pesticides
To avoid using a shipping container with pesticides, pay a little bit more and buy one that is known to not have any.
Some people will buy new, unused shipping containers that don’t have any toxins.
Like buying containers without lead paint, there will be an inherent peace of mind and savings to remediate the toxic gases.
To find out if the shipping container has pesticides, check the tag on the door of the container. It might say that it was fumigated with certain pesticide. Or, ask the distributor or manufacturer while referring to the manufacture’s number and serial number on the tag.
Method Two: Remove the Wood Flooring
Be sure that the existing wood flooring has pesticides in it before spending the time and money removing it.
This method can be expensive and time consuming. Special tools and procedures need to be followed when removing hazardous materials such as the contaminated wood flooring.
But, it would rid the shipping container one and for all the pesticide in the existing wood flooring.
Method Three: Epoxy over the Existing Wood Floor
Applying epoxy over the existing wood flooring would be cheaper than removing the wood floor.
The epoxy will need to be non-porous and solvent-free so it will seal all gases from the wood flooring.
The epoxy floor will act as a vapor barrier over the wood floor.
The wood floor will need to be prepped per the epoxy manufacturer’s recommendations before applying the epoxy over the existing wood floor.
Do not sand the wood floor before applying the epoxy because it could release toxic particles from the that could be hazardous to humans.
The finished epoxy flooring usually has a shiny finish and can be low-maintenance.
Method Four: Install a New Wood Floor Over the Existing Wood Floor
Install a new solid or pre-manufactured tongue and groove wood floor.
This new floor can be pre-finished. Pre-finished wood floor eliminates the need to add smelly lacquer on top of the new wood flooring after being installed. It also will save time during construction.
Before installing the new floor, the existing plywood floor needs to be clean, dry, and structurally sound.
Polythene lining should be placed over the existing plywood floor. Tape and seal all of the seams of the lining over the existing plywood. Also seal over the lining to the steel side walls of the shipping container.
The polythene lining will act as a vapor and moisture barrier. Be sure that there are no gaps that would allow the existing wood floor to off-gas into the living spaces above the new finished wood floor.
Then, install the new wood flooring over the sealed lining.
Method Five: Pour Concrete Over the Existing Wood Floor
Pour a 4” thick reinforced concrete slab over polythene vapor barrier lining.
The polythene vapor barrier lining would need to be taped and sealed as mentioned in method four above.
Welded wire fabric can be used as the reinforcing and can be welded to the sides of the shipping container before pouring the concrete.
The finished floor can be exposed concrete. the concrete could be stained, polished, and/or colored with colored aggregates or paint.
Or tile could be placed on top of the concrete. Be sure to coordinate the additional finished floor heights at door saddles and thresholds. The tile could raise the undercut of the doors by a half inch or more.
Hazard Three: Off-Gases from Chemical Cargo
Even if the shipping container does not have lead paint or pesticides in them, there may be residual off-gases from hazardous chemicals shipped as cargo in them.
Check with the distributor or manufacturer to find out what was shipped in the shipping container you are considering to use for you home. If there are no records to show its history, then consider not using that container.
Refrigerated and thermal insulated shipping containers are often used to ship pharmaceuticals and biological cargo. Therefore, it is not recommended to use these for most home designs.
Hazard Four: Structurally Damaged Shipping Containers
Shipping containers are designed to be used for many years at sea. Some are used for 9 years or more. The more they are used, the more exposure they have for rust, dents, and damage to the structural members and waterproofing of the containers.
See my blog post for structural tips to look for when choosing your shipping container for your home. Click here to read that post.
Conclusion
Saving time and money are important considerations during the shipping container selection process.
But it is most important that end user of the shipping container home continues to become well informed so that the health and safety of those who will be living in them will be protected.
Larry Lane has been a licensed architect for over 30 years. He is designed projects big and small for individuals and companies throughout the world. He lives in New Jersey and is also the author of the book journal, “The Designed Home.” His portfolio can be found at Larry Lane’s architecture port folio