It may not be the first thing you think of when someone mentions a house made from shipping containers, but a frequently asked question from those seriously considering one is, do container homes rust?
Do Container Homes Rust? Yes, container homes can rust, but this rusting is not necessarily a problem. In the same way, as with any other construction materials and designs, container homes need regular inspection, maintenance, and repairs. Look after your container home, and there’s no reason why it won’t last for decades.
However, the fact that they can rust is only part of the story. Let’s take a deeper dive into the world of shipping container home rust.
What Are Shipping Containers Made From?
Shipping containers are made of steel, a combination of iron, carbon, chromium, and a few other elements smelted together to form a robust and weather-resistant metal. Steel comes in many forms and strengths, depending on the additives mixed with the iron.
How Do Shipping Containers Rust?
The steel used for shipping containers is Corten steel. Corten is a combination of CORossion resistant and high TENstile strength. When exposed to the elements unpainted, Corten steel develops a thin, protective outer layer of rust which prevents deeper corrosion.
When shipping containers are made, the outside is painted to prevent any rust. However, if the paint chips, cracks, or flakes and the steel underneath is exposed, the Corten steel causes a small, localized area of rust, much like a scab, and prevents the corrosion from spreading or eating more deeply into the steel.
Types Of Container Home Rust
Typically, there are two kinds of rust in container homes. Chemically they are the same; the difference is in the location of the rust and what it means for your container home.
Structural Container Home Rust
Structural rust is the more severe issue of the two. In structural container home rust, corrosion has begun to eat into either the floor supports, the side rails of the walls, or both.
The containers’ floors are especially prone to rust as they may have sat in water during their sea journey. When you are in the process of choosing a container in which to build a home, be sure to thoroughly inspect the underside and the floor supports for any signs of rust.
Significant structural rust can be a safety hazard, leaving your container home unsafe. It can also require extensive and expensive repairs, sometimes over and above the worth of the complete container home.
Non-Structural Container Home Rust
Non-structural rust can be more easily dealt with. Rust in areas that are not structurally significant can be either treated or removed and patched, depending on the extent of the damage.
What Is The Best Climate For A Container Home?
Corten steel requires wet and dry cycles of weather to stimulate the protective oxidization process. A climate that is either too dry or too wet will not allow the steel to “do its thing” and protect itself.
Likewise, an exceptionally wet or humid climate will increase the likelihood of rust and significantly reduce the lifespan of your home.
Finally, despite the fact they are built to spend a lot of their time on ships, containers do not do well in saltwater environments. Most specialists recommend you avoid creating a container home within three miles of the seashore.
How To Prevent Container Home Rust
In addition to not building in a climate where the steel will not develop its protective layer or where problematic rust will be more likely, there are other ways to prevent or minimize container home rust.
Choosing The Right Container
It can come as a surprise to many people that not all shipping containers are precisely the same design. The dimensions and placement of critical elements are standard, but the way in which the cladding is molded, the bends, dents, and protrusions are not standard.
Consequently, it’s important to carefully inspect any container you are considering as the base for a home.
During the design phase of your home, identify any areas on your container that could allow rain to pool or otherwise trap water. If you find anywhere that leaves or other debris has gathered, this is a location where rust is more likely to develop.
If you have purchased a used container, take up the existing floor and replace it with a new one. This allows you to apply rustproof to the floor and floor braces of the container. It will also ensure that you do not live in a home where the floor is contaminated by any chemicals previously carried in the container.
Consider how the home is oriented on your plot. If possible, ensure your container is angled in such a way that there is the smallest possible area facing the direction from which the wind and rain drive.
Consider a pitched roof for your container home. An overhang will minimize the amount of rain that lands on the top of your container and the walls.
Don’t place your container home directly onto a slab foundation. Not only does this increase the chance of water becoming trapped under the base and rusting your home, but it also
makes inspection and repair difficult.
Instead, keep a crawlspace under your container home to allow for easy access and regular maintenance.
To paint the inside of your container home, it’s best to use marine-grade, direct-to-metal, waterborne paint. This will minimize the chance of further rust developing on the inside of your container.
There are four types of insulation you can use in a container home:
- Wool insulation is effective but expensive.
- Insulation panels are easy to install and can be easily cut to size.
- Blanket insulation needs wall studs to hang it between, which decreases the floor space of your home.
- Spray foam insulation will form a vapor barrier, thus reducing the chance of any mold, condensation, and subsequently rust.
It is especially important in a smaller home to have proper ventilation. Moisture from cooking, showering, and even breathing can build up on the walls of your home, running down to the base of the container walls and causing rust.
Planting trees, shrubs, or plants can help to shelter your container home from the elements. However, be careful not to plant too close to your home, creating new places for water to collect.
On-Going Rust A Container Home
As with other homes, it’s essential to carry out regular inspections and maintenance.
After excessive winds or other storms, take a walk around your container home and inspect it for any chips, dents, or dings. Even the slightest damage to the exterior paint can allow moisture to break through and cause rust.
Treating Container Home Rust
When you find any rust on your container, there’s no need to panic. However, it is essential to treat the rust as soon as possible to avoid unnecessary damage.
Sand down any rust with a perimeter of about one inch around the outside. Once you have sanded the area, you’ll be able to see if the rust is just a surface issue or has gone through the metal.
Surface rust can be removed, the metal underneath treated, and the spot repainted quickly and easily. If the rust has breached the skin of the container, it will require at least a spot weld for repair, something that should be left to a professional if you are not confident in your welding abilities.
If you’re thinking about a shipping container home, you might be asking yourself, do container homes rust? Well, yes, even though containers are made for use on ships and can spend months on end exposed to the elements, they can rust.
However, if you chose the container for your home carefully, ensure that the preparation and planning for your site is optimal, and treat any areas of rust or damage quickly, there is no reason why your container home shouldn’t remain structurally sound for many years to come.