How to Build an Underground Shelter

This post may contain affiliate links for products I recommend. If you click a link and buy something I may receive some compensation. This does not change the price you would pay.

“Man must put an end to war, or war will put an end to man”. I don’t know about you, but this quote terrifies me. Why? Because I know that if humans continue to fight, it will spell the end of our race. I hate to be so blunt, but that’s the truth. While you and I can’t do anything to stop a nuclear war, we can plan for the worst case scenario. In this article, I want to show you how to build an underground shelter. That way, when s*** hits the fan, and nuclear missiles are in the air, you’ll be able to live to tell the tale. Let’s get started.

Important Note: Just because the blast doesn’t kill you, this doesn’t guarantee you’ll survive. A big threat that you’ll need to deal with is radiation. Not only should your underground shelter offer good blast protection, but it should also isolate you from radiation. Heavier doses of radiation can kill you within minutes, while smaller doses can kill you within years. Needless to say, learning how to build an underground shelter should be a top priority.

Radioactive Fallout Will Be a Big Threat

Aside from the blast, your next biggest threat will be radioactive fallout. This is why you’ll need a shelter that is well-constructed. Believe it or not, hiding underneath a coffee table or in a basement can increase your chances of survival over the short-term. But only knowing how to build an underground shelter will guarantee your survival. The initial blast will probably kill a million people. Still, tens of thousands of will die from radioactive dust carried from several hundred miles away from the impact zone. If you live in the United States, realize that radioactive dust will most likely follow the jet stream, which is prevalent from west to east. Other factors like wind speed, temperature, and the size of the weapon also determine where radioactive dust will travel.

Understanding Radiation

I know you’re eager to learn how to build an underground shelter. We’ll get to that in a moment- I promise. First, I wanted to spend a few minutes talking about radiation. From a scientific standpoint, radiation is a type of electromagnetic radiation (EM). Like light, it’s simply a form of energy. Unfortunately, due to the high frequency/low wavelength nature of radiation, it can kill you. Here’s an illustration that shows how x-rays (a type of radiation) and gamma rays affect living tissue:

Not all types of nuclear radiation penetrate matter the same way. For example, slower-moving alpha particles can be stopped by a layer of clothing, while faster-moving gamma particles can do much more damage. Since gamma rays are “electrically neutral”, they don’t slow down when they collide with matter. As a result, they’re much more dangerous.

Being Inside a Building Can Save Your Life

I once found an illustration published by The U.S. Department of Homeland Security showing how taking shelter in buildings is the safest place to be during a nuclear fallout. I can’t find it any longer; however, at the time, I remember them saying that the deeper you are inside a building, the more protected you’ll be from radiation

How to Build an Underground Shelter

Some materials are better at shielding radiation than others. The thickness of the material also plays a big role. That’s why I recommend learning how to build an underground shelter using packed dirt. Not only is it cost effective, but it’s also very protective. According to Wikipedia, a shelter topped with packed dirt can reduce gamma rays to 1/1024!

One of the best and free guides I’ve seen for this is this pdf guide offered by HERE. It’s really good! Of course, they wrote it with the idea that you might buy one of their kits – but it’s all good! That may be one of the easiest things to do in the long run.

Now that you’ve learned about radiation, how it works, and how to protect against it, let’s get to the part we’ve all been waiting for- how to build an underground shelter. Keep in mind that I’m going to show you the bare nakedversion of this shelter. By this, I mean that I’ll show you just the basic design. It will be up to you to decide how you’re going to modify it to your liking. With that being said, let’s take get started.

How to Build a Pole-Covered Trench Shelter

There are hundreds of ways to learn how build an underground shelter. I’ll show the easiest (and cheapest) way. Don’t worry- it will still be durable and highly protective. It’s called the “Pole-Covered Trench Shelter”. With this shelter, you’ll dig a single trench, place logs over it, and finally, top it off with dirt. While the manual labor will be intensive, the final result should protect you during a nuclear fallout. It won’t be the prettiest shelter, or most comfortable, but it’s better than nothing. Let’s look at how to build it:


When learning how to build an underground shelter, you’re going to need the following:

  • Shovel (or Backhoe)
  • Saw
  • Wheel Barrel
  • Tarp
  • Wooden Poles

If you own a backhoe, consider yourself lucky. Without it, you’re in for some tough manual labor. Renting a backhoe will cost about $100-$350 per day. Depending on your physical ability, and your available manpower, this might be worth the investment. The wooden logs need to be relatively long (a least 20 feet). They should also be somewhat thick. Make sure that you have a minimum of 200 square feet of tarp. In a moment, I’ll show what to do with these tools.


Now it’s time to decide where you’re going to build your shelter. There are a few tips to keep in mind. First, make sure it’s nowhere near flammable material. When nuclear weapons detonate, they create thermal pulses that can ignite things as far as 20 miles (32 km) away. Also, make sure there isn’t a high water table. Otherwise, your trench will fill up with water. Florida is plagued by high water tables, so it’s not a good place to build one.  


When learning how to build an underground shelter, the size of your trench is completely up to you. As a general rule of thumb, make it somewhere between 10 x 10 x 10 and 20 x 20 x 20 (length x width x height). You don’t need to match these dimensions exactly. For example, your shelter might be 15 x 10 x 8 (or something similar).

Keep in mind that the deeper you dig, the more blast protection you’ll have. Once you’ve decided on the dimensions of your trench, dig your hole using backhoe or shovel. This will be the most time-consuming step of the process, but also one of the most important. Also, I’d highly recommend investing in a backhoe for this step. While costly, it will help you finish your shelter much quicker. Digging this shelter by hand will simply take far too long, and require a lot of physical effort. 


Once you’ve finished digging your hole, place the wooden logs across it. Separate them by about a foot when laying them across the trench. Very important: make sure the logs stick out a minimum of one foot from the trench (on both sides). This makes for a sturdier design. If they’re too short, the structural integrity of your shelter could be reduced. After you’ve mastered this part of how to build an underground shelter, it’s time to move on to step five. 


Take your tarp and place it over your wooden logs. Why is this step required? Well, you need the tarp there so that you can place dirt over the logs without it falling through into the trench. Basically, the tarp is there to ensure that absolutely soil gets into your living space. Make your dirt layer relatively high.

I’d recommend about 18 inches or so. From here, it’s just a matter of making your shelter hospitable. For example, you can build a makeshift bed, as well as build exits on both sides of your shelter. You’ll also want to think about ventilation, insulation, and increased durability. Learning how to build an underground shelter isn’t difficult in theory, but it will require a lot of manual labor.

Variations and Modifications

Many nuclear fallout shelters are built using this basic style. Why? Because they’re simple enough for the average person to build, yet strong enough to protect you. With that said, there are thousands of variations and modifications that you can add when learning how to build an underground shelter.

For example, some preppers like to add sheet-metal roofs in their shelters. Others like to reinforce the inside with concrete. You can also build ventilation and water systems. The complexity of your shelter really boils down to how much money you’re willing to invest, as well as how much protection you think you need for you and your family.