When people think of crazy preppers, they often think of underground bunkers, full to the brim with supplies, locked up beneath a Fallout-style hatch. But few of us have, or want bunkers. Why? It’s not exactly something you can build for cheap.
If you can afford to pay professionals to build one for you, sure, I suppose it could come in handy. These can run from $40,000 to over a million dollars though. To cut costs, some people try to do it themselves, but that is a really, really bad idea.
Without expertise, your bunker will just be a death trap. We’re about to point out all of the reasons why. The next time someone hears you’re a prepper and wants to talk to you about their make-shift bunker, you can send them this article.
1. Collecting Gas
Many harmful gases are heavier than air, and will collect in your bunker unless you take precautions.
Even if the gas itself can’t kill you, it will push out oxygen until you have nothing left to breathe, and that will kill you. Scenarios that people commonly prep for can involve gas release, like domestic unrest, war, and more. The Prepperu2019s Cann... Best Price: $13.51 Buy New $10.79 (as of 08:15 EST - Details)
Imagine pulling tear gas into your bunker. Then you should consider pandemic prep, if you want to use outside air you need a filter system. Or, you could consider gas leaks that wouldn’t normally merit a SHTF situation. A simple nearby propane leak, off-gassing from nearby septic tanks, or off-gassing from the soil itself, could all kill you.
2. Collecting Water
It’s not just about keeping rain water out of the bunker. It’s that you want to bury the bunker nice and deep to protect it from surface impact. But, you’re limited by the depth of your water table.
If it’s at all below the level of the water table, it will flood, concrete, steel, or other materials be damned. Sure, there is some top-notch engineering you can do to keep the water out, but it’s expensive. One solution is to put the bunker at ground level and then pile dirt on top of it, but you need very large amount of dirt to protect it from impact.
Speaking of sustaining impact, a bunker won’t survive the big one. Large earthquakes will certainly unseat it. Perhaps that’s not what you’re prepping for, but if you live in an Earthquake zone that’s something to think about.
If you have a bunker in the blast radius of a nuclear bomb, (the usual rationale for a bunker), it won’t survive. And, because you’ll have very little notice, if any, in the case of a nuclear bomb or explosion, you’ll have to be near your bunker when it goes off. Which means those of you who live in a potential attack location probably won’t be saved by a bunker.
You should use a competent engineer, preferably one with experience with subterranean buildings, to help plan your bunker. If not, it will probably cave-in.
Using old mine shafts or putting a shipping container into the ground (two strategies I’ve actually heard people try!) are two other good ways to get crushed to death. Another is to have a fire in the bunker. If you’ve made it out of steel, it will become more elastic and weaker under the heat and then buckle under the weight of the ground.
There’s another problem with using steel, in general, and that is that it corrodes when placed underground. You will want thick steel (that a shipping container just doesn’t provide), or you can avoid the problem by using a different material. Prepperu2019s Long-Ter... Best Price: $6.00 Buy New $6.00 (as of 08:10 EST - Details)
If you’re going to try to use steel in your own build anyway, try reading this technical manual about how to prevent steel corrosion (in pipe systems). In short: it’s tough.
There’s going to be a fire risk in your bunker, and it could even be in the walls. Many professional companies use Expanded Polystyrme (EPS) foam blocks which, according to Clarence Mason of Tempest Building Systems, are highly flammable and full of toxic chemicals in an attempt to make it less flammable. They should, ideally, be encased with something that is not flammable, but because they’re used in part to reduce costs, you might be tempted not to.
The rest of the fire risk will be from all of the things you bring into the bunker. Your power system could spark a fire, and your supplies could provide it fuel. And while you’ll probably (hopefully) also have fire extinguishers in your bunker, even a small fire could be a serious risk for the oxygen levels in your bunker. Fire uses oxygen, and you need to be sure your ventilation system can replenish that oxygen very quickly.
7. Air Quality
Speaking of ventilation systems, your bunker’s air supply is absolutely essential. What’s that saying: you can only last three seconds without air? Yeah, and plenty of things other than fire can interfere with your air supply.
Firstly, you need two ventilation systems, in case one breaks beyond repair while you’re in the bunker. Second, you need to protect the vents from birds, debris, and weather on the outside.
Then, you need to filter the air itself for many SHTF scenarios, including to protect from radiation, or people walking by who are infected from the pandemic, or debris from nearby collapsed buildings, the list goes on.