You probably landed here because you are curious to know how long a shipping container lasts. Maybe you are planning to purchase one for storage purposes. Knowing how long your investment is going to last is an intelligent first step towards your purchase.
The Short Answer to Container Lifespan
A steel container, which is the most common type, can last for 10 to 25 years. However, this is based on how you use it and where you place it. If you take good care of it, it can even last longer than 30 years.
How Long Do Shipping Companies Use Containers?
Shipping lines and rental companies usually keep containers as long as they save money. Most standard dry containers work in international shipping for about 10 to 15 years. After this time, the law does not force them to be destroyed. Instead, companies stop using them for ocean travel because they become too expensive to keep. The following things help a company decide to retire a container:
- Repair Costs: It eventually costs too much to fix old damage.
- Overall Condition: The container might be too rusty or worn out.
- Customer Needs: People paying to ship goods want clean, strong boxes.
- Efficiency: Moving older, slower units around is not always worth the effort.
Once a container is done with ocean shipping, it is not useless. Many are sold to people who need them for backyard storage, office space at construction sites, or building projects.
Factors That Affect Shipping Container Longevity
In order to make your container last longer, it is essential to know what makes it deteriorate.
1. Exposure to Saltwater and Coastal Air
The biggest enemy of Corten steel is salt. If your container is located near the sea or ocean, salt will hasten the formation of rust on your container. This will drastically reduce the lifespan to 10 or 15 years if you do nothing to protect your container.
2. Local Climate and Humidity
If you live in a tropical region, you will notice that high humidity will cause moisture on the surface of your container. This will hasten the formation of rust on your container. Moreover, condensation inside your container may cause damage to your container in the long run.
3. How Often the Container is Moved
Each time your container is lifted by a crane, stress will be applied to your container. If your container is used for international shipping, you can be sure it will be subjected to harsh weather. A container used for storage will last longer than a container used for international shipping.
Understanding Different Container Conditions
When you go to buy your container, you’ll notice that they all have different grades. These grades help you determine the life remaining in the container.
- One-Trip Containers: These containers are like new. They’ve only crossed the ocean once. They’ll easily last you 25+ years with little work.
- Cargo Worthy (CW): These containers are used but still meet international shipping criteria. They’ll give you 10 to 15 years of good life remaining.
- Wind and Watertight (WWT): These containers are older and no longer used for shipping. They stay dry inside. They’re great for budget-conscious storage.
- As-Is Containers: These containers may be damaged or feature heavy rust. The life remaining in these containers is unknown.
How to Extend the Life of Your Container
The life of your container can be extended considerably by taking the following steps:
Treat your container like a car. It needs regular check-ups.
Step 1: Build a Proper Foundation
Do not place your container on bare dirt. Moisture from the earth will seep into the container and rot the cross-members at the bottom.
Step 2: Control Rust Immediately
Check your container for scratches and dents. If you see rust, sand it down and apply a zinc-rich primer. This will seal the container and eliminate rust.
Step 3: Install Proper Ventilation
Ventilation is important for container longevity. Without vents, the “sweat” inside the container will cause the roof to thin out eventually. Adding louvered vents can significantly extend the life of your container by reducing the internal moisture buildup.
Step 4: Roof Maintenance
The roof of your container is the weakest part. Water will eventually seep into the container. Ensure your container is slightly tilted so water will run off.
Is a Used Shipping Container Worth It?
Buying second-hand is an excellent way to cut costs. Second-hand containers are usually removed from active service by shipping companies after 10 to 12 years. This means that they have a long life left before they become useless.
It is a good idea to personally view the second-hand containers before making a decision. Look out for major structural bows or holes that allow light to pass through. Minor dents are acceptable, but severe rust with flakes is not good.
The Role of Quality Control in Longevity
Quality control isn’t just done at the end. It’s done throughout the process. The quality of the steel’s chemical composition is checked first. They verify the Corten steel has the right copper and chrome content.
When welding the parts together, they use an ultrasonic test to locate unseen holes. This ensures water won’t seep inside the frame. The “light test” ensures there are no pinholes in the roof or the corners.
Common Problems That Shorten Container Life
You must be careful about the following problems if you want your container to last.
Roof Sagging
If you put heavy things on the roof, it may sag. This causes water to collect. The water causes rust. Always add supports if you want to put a deck or garden on top.
Door Hinge Seizing
Salt and dust may cause the heavy doors to seize. This makes it impossible to open. The hinges and locking bars must be lubricated every six months. This stops the physical damage to the door from forcing it open.
Floor Delamination
Marine plywood is durable but may peel if constantly wet. If you use the container to store refrigerated goods, be careful about moisture on the floor. The best way to preserve the floor is to keep the interior dry.
Comparison of the Materials Used in Shipping Containers
Not all shipping containers are made of the same material; therefore, their durability differs.
- Corten Steel: This is the standard material used in the majority of containers. It is covered with a layer of rust that protects it from corroding.
- Aluminum: These containers are lighter in weight and more resistant to corrosion compared to corten steel. They can be easily damaged by denting; however, repairing them is costly.
- Stainless Steel: These containers are used in the transportation of chemicals. They have the longest durability; however, these containers are rarely available in the second-hand market.
Choosing the Right Manufacturer for a Longer-Lasting Container
The following companies are leading in the manufacturing of top-notch units:
- CIMC, which is known as China International Marine Containers, is considered the world’s biggest supplier, as they use high-quality Corten steel making it globally available.
- Despite being a carrier company, Maersk manufactures brand containers that will serve the longest as they are designed to be durable enough to withstand years of use.
- The third company in our list is Singamas, an important producer, specializing in the manufacture of specialty units. Triton International operates the world’s biggest fleet and its used containers are considered premium due to their excellent maintenance.
- The last one is CXIC Group, famous for its large variety of ISO containers of high-quality weld and paint finish.
How Shipping Container Modifications Affect Lifespan
If you cut a shipping container to add windows and doors, you will be reducing the lifespan of the shipping container.
- Structural Integrity: Cutting the corrugated steel will reduce the structural integrity. You will have to add steel to the cut area to add support to the new opening.
- Exposed Edges: Cutting the steel will create exposed edges where rust will begin to set in. You will have to paint these exposed edges right away.
- Insulation Issues: If you do not insulate correctly, moisture will build up inside the shipping container. This will cause the shipping container to rust from the inside out, where you cannot see it.
The Environmental Benefit of Extending Container Life
By repurposing a shipping container, you are upcycling. It takes a tremendous amount of energy to recycle a shipping container and turn it into scrap. By repurposing your shipping container to last 30 years instead of 15, you will be reducing your carbon footprint.
There are many eco-friendly homes made out of repurposed shipping containers. These homes provide a solid foundation that is eco-friendly. Not only is this an eco-friendly option, but it is a long-term solution with proper maintenance.
In Short
With proper maintenance, your shipping container can last well beyond 30 years. You will have to ensure that the foundation is solid and that you do not allow it to rust. By following these easy steps, you will ensure that your shipping container is safe and dry.
Frequently Asked Questions About Shipping Container Lifespan
1. What’s the average lifespan of a shipping container?
Shipping containers are made of steel so their lifespan is typically around 10 to 25 years in a normal environment. With proper maintenance, containers in dry environments can even surpass 30 years of service.
2. How does being near the ocean affect the container’s lifespan?
Due to saltwater exposure, containers tend to break down faster near the ocean. Because salt spray can cause premature rusting, untreated containers may only last 10 to 15 years. To avoid this, containers should be washed regularly, and the exposed steel should be painted with marine-grade paint.
3. Is there any way to stop the bottom of my container from rusting?
The best way to keep the bottom of your container safe from rusting is to build an appropriate foundation instead of putting it on bare soil. Using concrete blocks, gravel, or railroad ties keeps the container higher than the ground, thus ground moisture will not contact the bottom cross members of the container and will not make them rot.
4. What is the importance of ventilation in the life span of a container?
Container ventilation is important to avoid the moisture that builds up in the container because of poor ventilation. This moisture will cause the container to rust from the inside and the container walls can be thin. Installing either louvered vents or solar fans will be great benefit and may increase the lifespan of the container.
5. How structural changes like windows in containers can affect the longevity?
Modification of the walls involves cutting, which compromises the structural integrity and increases the chances of rust at the point of the cut. To avoid rust, the cut edges must be painted and primed as soon as possible.
6. Is the wooden floor more durable than the steel walls?
The floors of shipping containers are made of marine grade plywood which has been treated with insecticides and sealed to avoid rotting. If the floor remains dry, the plywood will be just as durable as the container’s metal facade. If the plywood gets wet, it will begin to spall, and replacing the floor will be costly.
7. How long do Reefer containers last?
Reefers will survive between 10 and 12 years when used in marine shipping. This is due to the fact that the refrigeration equipment as well as the walls degrade relatively fast compared to the standard metal ones.
8. How long do Tank containers last?
Tank containers can survive for up to 20 or even 30 years due to the fact that they are made of strong stainless steel and are regularly inspected.
