Does a Buried Shipping Container Make a Good Bunker?

Not all bunkers are built for the same purpose. Some people take their survival bunkers to an extreme level, and while that’s not necessarily a bad thing (to each his own, right?)

I don’t think a successful bunker has to have fifteen forms of security protection and fifty years' worth of food storage. I believe that if you build something to meet your basic needs and safety, then you’re already ahead of most of the population.

Survival bunkers are typically made of concrete and built underground to keep people hidden from aerial and ground view.

People build bunkers for different reasons, such as to survive an economic collapse, a nuclear attack, or to ride out natural disasters, like tornadoes and hurricanes. Different scenarios may require slightly different structures.

So can you use a shipping container as an underground bunker? It depends.

If you’re planning a short-term shelter (such as for natural disasters) you can make it work! The upside? It’s fairly cheap to buy a container. The downside? It will take a lot of cleaning, sealing off toxic chemicals, and strengthening the entire structure to make it last for years to come.

This can be a costly endeavor. For storm shelters, shipping containers are better used if they’re anchored above the ground.

If you’re preparing a long-term hiding place (such as in the event of a societal collapse), you’re better off building with different materials.

More about shipping containers in a minute. First, we must ask ourselves, what makes a good bunker?

An effective bunker has to have the capability and supplies to survive for as long as possible taking first into consideration the scenario you’re preparing for.

1. It must be buried in a safe location.

Building your bunker underground is a must but it’s very important to choose a location that can be accessed easily and without much attention. For end-of-the-world shelters, choose a location that is in the middle of nowhere and unlikely to be seen by people driving on nearby roads.

For natural disaster shelters, build an easy access through your home or backyard. One important thing to think about- your bunker should ideally be buried in a higher point of the property to prevent overflowing and flooding.

2. It should have an inward-opening door with good security AND a backup exit. 

Make sure the door is reinforced from the inside. Experts recommend getting a bulletproof door. This is great if you’re going to be using your shelter for societal collapse. Things will most likely get crazy in the outside world and you’ll be better off taking stricter precautions.

A backup exit is extremely wise. If a natural disaster causes debris to block your main entrance you will need another exit route. In a more extreme scenario, imagine life after a societal collapse. If someone finds your bunker, chances are that your entrance is going to be found first. In either case, make sure your backup escape route is equipped with a camouflaged door.

3. It should have a peephole.

Every bunker needs to have the means to see outside without going outside. Install a camera that will allow you to check out the outdoor situation without having to leave the bunker. A peephole camera can strengthen your security measures by showing you if someone is coming near your hiding place without blowing your cover.

4. It should have a comfortable and safe living space.

Consider who you will be bringing with you into your shelter. Do you have children or pets? Make sure the living space you establish is as comfortable as the life you currently live.

Some people have built their shelters with LED tvs and other fancy gadgets. If it’s in your budget to do that, then go for it! But for those who want to build a basic short-term shelter for the family, consider board games, books and music to keep you entertained during the time that you’re sheltering in place.

5. It must be built out of heavy-duty materials.

When you have a structure buried six feet under the ground, it’s a no-brainer that it has to be strong enough to withstand the pressure of the soil above and around it.

Take extra consideration for earthquake-prone areas, where your shelter must be able to resist ground shock.

If you’re planning a nuclear fallout shelter, make sure that you’re deep enough in the ground to be protected from radiation.

If the soil is especially wet in the area where your shelter is buried, you may have to build an additional surrounding structure so that the sides and ceiling don’t cave in as the soil pressure increases.

If your walls or ceiling cave in over a period of time, you risk cracks, and with that come many other problems.

6. It must have an effective air circulation system.

Airflow is absolutely necessary for survival. There’s no way around it. Good ventilation improves air quality which subsequently improves our health.

The lack of proper ventilation can cause condensation, mold growth, an increased amount of toxic compounds and bacteria, and possible suffocation.

An air exhaust pipe, or whatever other form of air source you choose, needs to have a contaminant filter. Make sure the underground vents are camouflaged from the outside.

7. It must have plenty of food, snacks, and potable water.

Some people have built their bunkers with a means of growing their own fruits and vegetables. If you’re planning a shelter for short-term use, you can do well with a few buckets of emergency preparedness food that is specially made to last up to 25 years.

As far as water goes, you’ll need a solid supply of water for the length of time you’re sheltering in place for, whether that is for a few days, months, or several years.

You’ll need water not just for drinking, but also for preparing food and cooking. Just like air filtration, water should be filtered to remain free from all contaminants, including radiological ones.

8. It must have proper waste and water management.

If you’re not sheltering in place for too long, you could survive well with a chemical or waterless toilet. A very cheap option would be to make your own DIY toilet with a plastic bucket. This is a new revolutionary way of safely disposing of human waste during emergencies.

For long-term shelter, you’d have to look into more long-lasting waste and odor management systems. A composting toilet may be one of the best options if you’re on a budget.

There are other enhanced ways to handle the disposal of waste, like incinerator systems or large septic tanks, but these are much more costly. Greywater needs to be disposed of safely as well.

Ok, since we have a general idea of the main features that a bunker should have, now we can get back to the topic of shipping containers.

In the last few years, homes built out of shipping containers have risen in popularity. Other than their modern look, they’re also much cheaper to build than traditional homes. This stands true for bunkers as well. Buying a used container is inexpensive.

The debate now lies in whether or not one of these containers would be a safe option for a bunker shelter.

There are two major risks associated with shipping containers however when they’re properly cleaned out and protected with the right materials, they can be safe to live in.

Shipping containers are usually coated in paint to prevent rusting and other deterioration from the constant exposure to the outdoor elements.

This chemical is toxic when inhaled for a long time. Since there is no way to remove the paint from the container itself, proper insulation is required to minimize this risk.

The kind of paint you use for walls and outdoor deco is not strong enough to protect you from these chemicals so you’ll have to cover it up using spray foam insulation on the internal walls.

The floor of the shipping container is another topic of concern. Many containers are sold with a wood floor that has been previously treated with chemicals that are also toxic.

You have two options here but keeping the floor as is, isn’t one of them. If you want to keep the floor, you will have to install a protective barrier directly over it, such as non-breathable flooring underlayment, and your own flooring above that.

Your best option would be to get rid of the floor entirely and replacing it with marine plywood and install a new floor above that. This will greatly reduce the risk of these toxic substances contamination your air supply.

If you haven’t purchased a shipping container yet but are considering it, ask the manufacturer ahead of time not to paint the exterior of the container or treat the floors. If you have already purchased a container, contact the manufacturer and ask them exactly which chemicals were used.

A bunker is made to be buried underground and the ground, or dirt, weighs a lot! Some bunkers are buried so deep that they’re covered in three to six feet of dirt. When water is involved, the damp soil will obviously weigh much more.

A shipping container is extremely sturdy but it was never designed to be buried. It’s certainly not strong enough to withstand the constant pressure of dirt pushing on the sides or the roof. If the roof or sides cave in slightly, you could face serious problems, including cracks, rust, rodents and water getting in.

The solution here is to reinforce the inside and outside of the container with a frame to create a stronger overall structure. Consider also where your bunker is located. If it’s possible for a vehicle to drive over it (if it’s camouflaged well enough) then imagine the amount of pressure that will add.

While there’s no structure that is 100% fireproof, the very nature of a shipping container’s structure is inherently fire resistant. It’s recommended that you use flame retardant insulation and protect the inside/ outside walls with a fire rated sealant to provide extra protection from internal fires. As always, keep a fire alarm installed and a fire extinguisher nearby for emergencies.

No, they’re not. Underground temperatures are typically more stable year-round which means that throughout the summer temperatures will be a bit cooler and during winter a bit warmer. This is a huge benefit but some form of insulation is required regardless, no matter what climate you live in.

Shipping containers are coated with a substance that makes them waterproof. These containers travel for many days in the deck of a ship in the middle of the ocean. They’re built with heavy duty materials that keep them protected from the ocean water and rain.

Equally important as the waterproof question, is knowing whether or not a container is airtight and water sealed. Before shipping containers are sold to an individual, the manufacturer will inspect it to make sure that the seal is secure and the container structure is in good shape.

If you're going to bury your shipping container, on occasion you should check for cracks, dents and rust. Cracks can cause water to start creeping in and if it’s not fixed early enough, critters may follow. Rust will cause rapid deterioration to your container and heath problems for you.

The process of building an underground shelter is not only tedious but also expensive, so it’s imperative that whatever you choose to build your shelter out of has the ability to last a long time. Under the right conditions (above the ground), a container can last up to 30 years without maintenance.

When used as underground shelters, the container may last considerably less if the soil around it is very damp. Like before mentioned, these containers weren’t designed to be buried, so you run a risk of the metal getting corroded in acidic soil. Proper maintenance will increase the life of your container so you’ll have to inspect it periodically for wear and tear and always after significant storms and natural disasters.

If you’ve made up your mind and are choosing to build a bunker with a shipping container, your next question might be “How do I do this?” As you can probably guess, it takes a lot of digging and ground work.

While I don’t have any personal experience in doing this at home I found someone who successfully did it and documented his process. Notice he went to great lengths to prevent his container from caving in. You can check him out here:

I have read several accounts of people who built their homes out of shipping containers and they attest that their homes were able to withstand category 3 to category 5 hurricanes. The structure of a container is typically much stronger and more resilient than a traditional home.

Don’t only take my word as a guarantee that a container will be the best structure to keep you safe during a natural disaster but see what other experts have to say. You may find the general consensus being that an unmodified container is probably a safer bet. Although shipping containers may need enhanced structural support, they’re known to be very durable and withstand storms.

Depending on the disaster you’re preparing for, research the best ways to anchor your structure (or container) properly to the ground and determine what other security measures can be used to make your storm shelter as strong as possible. Every disaster is different of course, so what is recommended for hurricane preparedness may be different than earthquake safety, for example.

Before building your ultimate survival bunker, determine what your primary needs are. What purpose will your bunker have…are you preparing for a natural disaster or an economic collapse?

If you’re planning a storm shelter, a reinforced shipping container should do the job just fine but it may not be worth the hassle and cost of strengthening the entire structure. It’s not impossible but it might not be worth it in the long run.

In the case of storm shelters though, you’re probably want to reconsider your plans and build an above-ground shelter instead.

If you’re planning for a country-wide collapse, you’ll definitely want to consider a different bunker option. It’s not wise to even risk the possibility of caved roofs or walls. Unless you’re an engineer and can figure out the perfect way to strengthen it properly, it’s probably safest to go a different route.

Talk to professionals in the bunker-building industry who can better advise you on the equipment you will need.

Don’t let this discourage you entirely because bunkers are a great idea. It’s just necessary to build it out of the right materials to prevent the real disaster of having it collapse on you when you most need it.