Shipping Container Homes can withstand tornadoes ranging from F0 (40-72 mph) to F2 (113-157 mph) strong. This is if they are properly fastened with heavy duty industrial cables to a stable foundation like concrete slab or basement. However, like all homes, windows are susceptible to break and shatter with low strength tornadoes, causing the wind to enter one’s home and create structural damage by lifting the roof off. This then leads to a collapsing of the walls. It is always advisable to have a safety plan that secures an underground, windowless site, (often a basement) as a safe place to wait out the tornado. Ensure all family members are aware of where it is and ensure the place is accessible in times of disaster.
Containers aren’t the safest structures to be in if not tied down properly or filled to the brim with heavy goods. Without all this weight, the container can tip or flip over in strong winds, tornados and other extreme weather. This poses harmful to those in the container or near it.(1)
To make absolutely sure you’re securely anchoring your container home to the ground, attach it to your foundation with heavy duty straps, cables or industrial twist locks. Installing wind braces also help in stabilizing the home into position.
Being made of steel, container homes are more lightweight. This is beneficial in some cases but in others, like tornados, not being as heavy as a traditionally built home makes it easier to be tossed by the wind. On sea, this may mean sliding around or off the ship. (2)
Yes, it’s true containers are strong, being able to survive extreme conditions at sea for months. Steel framed buildings can withstand up to 170 miles per hour of winds while wooden frame homes only take up to 150 miles per hour. Being made of steel, this makes container homes a better survival rate than wood based prefabricated homes like manufactured homes. (Check out Are Manufactured Homes Safe in a Tornado?)
The heavy weight of containers also helps in being harder for winds to push. However, being made into a home means we’ll have to puncture this strong frame to put in some doors and windows — the most vulnerable part of any type of home.
Even though your structural frame will hold steady, the windows can easily shatter. It can cause more damage internally once the wind penetrates your windows, which withstand only around 75 miles per hour. This is damaging as the wind inside can create an internal air pressure, cause the ceiling to lift the roof off and be carried up and away. Note that prior to this, the roof may have already been weakened by its shingles and decking blown off. However, when completely gone, this may cause the walls to start collapsing, taking your home and its contents with it. (3)
Tornado wind speeds are ranked according to the Fujita-Pearson scale, as seen below: Information and ratings are taken from Can a Shipping Container Home Withstand a Tornado? | 4 Great Ways to Protect Your Container Home from Tornados | Container Home Hub: (3)
- F0 (Gale tornado): 40 to 72 mph
- F1 (Moderate tornado): 73 to 112 mph – with F0 comprises 80% of tornadoes in the United States and container homes should be able to withstand but windows may shatter
- F2 (Significant tornado): 113 to 157 mph – Home’s frame and roof may survive
- F3 (Severe tornado): 158 to 206 mph – Can cause structural damage and wreck container homes as these can even uproot several trees and flip over trains.
- F4 (Devastating tornado): 207 to 260 mph
- F5 (Incredible tornado): 261 to 318 mph
Regardless of the type of home, all safety risks homes can encounter are your damaged roofing, shattered windows and broken doors causing internal air pressure and structural damage. Your roof is usually the first part that is susceptible to being weakened by the elements. Not to mention, all buildings are also subject to flying debris, which causes the most deaths and injuries.
Stabilize and strengthen your home’s performance against tornadoes by integrating the following features into your container home: (3)
- Build on a strong foundation or concrete slab your container home can attach to securely. Anchor or bolt down each corner to the concrete footing. This helps your home be ready for any pressure changes.
- Consider having a basement foundation (if budget allows) for a more secure evacuation space.
- Opt for DP 50 windows, these can withstand up to 200 miles per hour of winds. If you can’t afford windows rated at DP 50, get the highest number you can afford. “The DP rating measures the window’s structural load, water resistance, and air infiltration resistance.“ (3)
- Choose metal roofing or asphalt shingles. Metal roof panels last longer when facing strong winds.
If you’re still in the process of building your container home, try and retain as much as you can of the original form itself. Lessen how you puncture its corrugation for windows and keep the heavy duty doors. These can double as your home going into “lock down mode” when a calamity strikes.
You can also try to plan the windows and doors to be located behind the container doors themselves. Though note this may lessen your indoor floor area, but give you a full lockdown even for when you need to leave your home unattended.
Protection of your container home can even be implemented on your site landscaping. Partially burying your home is another tactic of literally grounding your container. This involves extensive sitework and treatment for the metal, however in all the digging, you create berms. Berms help divert winds and lessen how much wind force gets onto your home itself. This prevents the tornado’s full power from picking up your home and tossing it aside! (4)
Shipping containers, being shipped across continents, were made to survive storms at sea, salty air and waves more than tornadoes. Therefore, more often than not, if your container home cannot accommodate all safety precautions listed above, or you’re already living in one, it’s best to secure an evacuation site your family can safely get to. Search places with these qualities and make a plan: (4)
- Underground: This is why basements are preferable as your foundation. As basements often don’t have windows, this further reduces the risk of the wind entering and damaging your home.
- Away from Windows: As often mentioned, these will be the weak links and points of entry into your home. Identify a spot farthest from any window like under the stairs, a small bathroom or in the tub! In a commercial or school building, this may be your interior hallway.
For anyone living in a tornado prone area, always have a safety plan of where you can evacuate to, whether designated emergency shelter or basement. Also check to be sure this place is accessible when weather warnings arise and that all family members know how to get there. (2)
- Port Shipping Containers. (2021, July 29). Will a shipping container survive a tornado? – port shipping containers will a shipping container survive a Tornado. Port Shipping Containers. Retrieved August 2022, from https://portshippingcontainers.com.au/blog/will-a-shipping-container-survive-a-tornado
- Shipping Container Jungle. (2022, March 14). Using Your Shipping Container As A Tornado Shelter – Can It Work? Shipping Container Jungle. Retrieved August 2022, from http://shippingcontainerjungle.com/can-a-shipping-container-be-used-as-a-tornado-shelter/
- Rose, G. (2022, August 8). Can a shipping container home withstand a tornado?: 4 great ways to protect your container home from tornados. Container Home Hub. Retrieved August 2022, from https://containerhomehub.com/can-a-shipping-container-home-withstand-a-tornado/
- Sisi, J. (2021, September 1). Are shipping container homes safe in tornadoes? The Supermumma. Retrieved August 2022, from https://www.thesupermumma.com/2021/09/are-shipping-container-homes-safe-in-tornadoes.html