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How to Build a Low Cost Earthbag Tornado Shelter — 16 Comments

  1. I just bought and read the book Easy Cellar from easycellar.net. It is just an earthbag shelter half buried underground with a flat wood roof and center wood support beam and a foot of soil on top. I feel that I learned just as much/more from this website/blog. Thank you for this!

        • Yes, of course it’s safe. That’s why militaries all over the world have been building with sand bags for hundreds of years. They’re bomb and bullet resistant.

          Search the name of your state plus keywords ‘sand bags’ or maybe try ‘poly bags’. Try to find them as locally as possible because shipping is expensive.

  2. Has anyone been through an f5 tornado in one of these? If so, is it half berm or full berm? I have bad anxiety when it comes to tornadoes so before doing this I need to know what it is like in an f5.

    • You can build with no berm, partial berm or full berm. It doesn’t matter. Talk to any engineer. The wind will just blow around it because there are no flat surfaces for pressure to build up. The biggest weakness is the door, and that’s easy to secure with a steel bar inside.

      Edit: Use a full berm if there are big trees nearby that can fall on the dome.

  3. How many feet of an earth bag shelter need to be underground? I’m absolutely terrified of tornadoes, and I’m kinda in a panic to get one built fast. Please tell me the cheapest and easiest way. I’m on a very tight budget, but it has to be safe enough for my grandchildren. I’ll dig it myself if I have to.

    • How big do you want it? Roundhouse or dome?

      Free on how to build a roundhouse: http://www.instructables.com/id/How-to-Build-an-Earthbag-Roundhouse/

      You could add a ferrocement dome roof on top of the roundhouse. You could bolt a strong roof on top of the ferrocement dome to make it more durable and look better. Even if the roof blew off you’d still be protected with the dome roof.

      Wall depth: Dig a rubble trench and put about 3 courses of gravel bags on top. Continue with gravel bags until you’re above the level where moisture will cause problems (from splash or drifting snow).

      Add a really strong steel door, ventilation, bring in water and electric. Keep it small so it’s fast and easy to build. Add vertical rebar pins down through the inside of bags. Tubes are stronger than bags. Do everything correctly and you should survive a direct hit and even falling trees on top.

      In my opinion, every home in hurricane and tornado areas should have a shelter like this. Isn’t safety and peace of mind worth $500 to $1,000?

  4. No matter what material be used, the shelter must be at least half buried. You and the loved one must be under the ground level. Can be flooded? Not true. A $60 sump pump with a 120 V line, makes the difference.

  5. I think this is an excellent idea. Most people are not aware of it, but the civil defense shelters built in the last half of the 20th century in the US have been shut down and are not maintained.

    Switzerland has working nuclear bunkers for their entire population, located in every neighborhood throughout the country. In Israel, all new construction is required to have a bomb shelter built in each house/apartment.

    Now, we don’t have the same war worries that they do, but when a tornado hits, it is much like a bomb going off. All stick-built structures in the area are demolished, only the stone, concrete and brick structures survive. This should teach us something. If you live in tornado country, you really need to have a storm shelter nearby, if not in your house or yard. Buildings can be replaced, lives can’t, and earthbags offer an economical way of providing shelter and safety for yourself and your family.

    Always keep it stocked with appropriate emergency food, water and first aid supplies, and keep these fresh. A storm celler makes a good food storage unit. Buy, stock, and use the supplies that you normally enjoy, comfort in a disaster can be a real life-saver.

    • Well said. Your point about stocking some supplies is particularly important. You need space for people and supplies.

      And for those wondering if this will hold up through a tornado, don’t worry. Domes are one of the strongest shapes in nature and will easily withstand tornadoes and hurricanes. Our dome has about 20 truckloads of soil on top and it has never budged at all in several years. We could put another 20-100 truckloads of soil on top and it would not change a thing.

  6. Attention earthbag builders. The tornado shelter business is booming as documented in the Yahoo article. This could be a good time to build earthbag tornado shelters for profit. Even with paid labor, earthbag domes would be far less expensive than reinforced concrete storm shelters.

    • I’m sure the makers of the reinforced concrete shelters will be the first to say only theirs has been tested to tornado scale winds. “why take a chance with anything else” they’ll say. Has any earthbag structure taken a direct hit from a F1-F5 Tornado? My whole house will be earthbag so its a mute point for me :)

      • Every topic imaginable has been covered on this blog or EarthbagBuilding.com.

        Blog post on wind test: https://naturalbuildingblog.siterubix.com/2011/05/03/wind-testing-of-earthbag-wall/

        Testing page: http://www.earthbagbuilding.com/testing.htm

        Wind test: 2011 Ross (U Florida Engineers Without Borders): Wind Testing of Earthbag Wall Abstract Out-of-plane displacement of 2.1 m ht x 3.6 m (7’-6” ht x 12’) unplastered, braced wall; tamped silty sand (no clay); solid poly bags 35 cm (14”) thick wall

        Note: The earthbag wall passed the test despite being poorly built with loose sand instead of the recommended moist, tamped clayey/sandy soil that’s allowed to dry. The final result should have been something approaching rammed earth, not loose sand bags!

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