Tornado Storm Shelter

My wife and I now live in Tornado Alley (central southern Missouri) and the house we just moved into has no viable way of taking shelter.

I used my foundation plugin and basic SketchUp tools to quickly mockup a tornado storm shelter:

  • 6x8x7.5H interior dimensions
  • 12" thick reinforced concrete walls and roof.
  • 30"x72" door opening with steel door
  • integrated shelves/seats/beds

I have’t determined yet where the grade line will be but I want to have it at least half buried in the hill side next to our house, so some excavation will be required. This will also affect the final geometry required for the stairs. L-shaped entrance also helps protect the door from large flying debris (ie. vehicles).


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Have,always wondered how to best provide for ventilation in one of these things ? I suppose the less exposed the better … good luck with it. :+1:

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I wonder how to protect from water seepage both from the ground and down the stairwell. Maybe a drain and sump pump for the bottom of the stairwell and membrane under the foundation.


I like your thinking. I realize tornados don’t typically last for long periods of time, but I imagine you could be stuck (literally, debris blocking the door) So you may want to provide storage for water, and perhaps a toilet (if only a 5-gallon bucket with a seat) Perhaps a Cap over the stairs to help keep debris from blocking the door. I’m probably over thinking it…

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May as well go the whole hog and turn it into a full blown man cave! Make it useful the 99.9% of the time when not being pummeled by a tornado.


I was actually thinking about framing up a small shed on top of the concrete structure for storing my riding lawn mower and other garden tools.

I like the idea of a vapor barrier under the concrete and then coating the walls with the typical foundation/basement coating. Also a drain pipe that collects the rain water and sends it down the hill away from the structure.

I will be installing a ventilation pipe as well as conduit for electrical back to the house.

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Won’t the tornado just rip that off the top like opening a can of beans?

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Building underground is difficult. The structure has to withstand lateral loads from the ground and if you want it to be dry, it needs tanking.

What about building a pyramid above ground instead? I don’t mean the whole Rameses II, but something that is heavy and hard to shift.

Or store it nearby so you can filter it for drinking water from inside the bunker in case you will have to stay inside longer then expected? :thinking:

Welcome to Missouri. If you ever make it to St. Louis, let me know so I can buy you lunch for all the help through the years. There are a number of companies in the region that manufacture shelters. Most are aboveground steel structures. It would be interesting to compare cost. They might be a good resource for ventilation fans and accessories.


I did a full basement under a 2 car garage once with precast concrete plank. I first learned about plank and building with it on a 5 story apartment building in the 80’s. When I asked the precast company if the ever did this in a residence, they said, “Oh, yeah, we get a couple a month or so.”

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Yes, it would, but since I would already have a square patch of concrete I might as well put something on it.

When I get up that way I might have to take you up on your offer one of these days.

I have looked at some pre-manufactured shelters, but so far building my own seems more affordable and interesting. I may find though that it is actually cheaper just to buy one.