How to Build Your Own Underground Bunker

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The threat of nuclear war, terrorism, and natural disasters are what most of us worry about. Some say that it’s not a matter of if but when the next major catastrophe will happen.

One way to be prepared for any disaster is by building an underground bunker in your backyard.

But what do you need? How big can you make it? And how much does it cost to build one yourself? Check out this blog post for answers to these questions and more!

Step 1: Location and Safety

You can’t build a bunker in what will eventually become your grave, so the first step to building an underground bunker is deciding where it should be.

The area should include enough space for ventilation so that any fumes from the construction process are properly vented, and it should also be in a location with decent soil, not rocky or sandy.

Step 2: Tools and Equipment

The next step is to list all things you’ll need to build your underground bunker.

This includes shovels, hand pickaxes, power tools (drill and sander), ventilation system supplies, lumber, plywood, drywall screws, concrete/cement board, glue for the concrete/cement board, mortar mix, roofing materials, insulation, heavy-duty plastic sheeting material.

You can also add other amenities, such as a decontamination kit, weapons to protect your family members from intruders, oxygen tanks to keep you alive in the event of contaminated air, and medical supplies.

Step 3: The Process

After you have chosen the location for your underground bunker and have gathered all your necessary tools and materials, it’s time to dig (keep in mind where you position the entrance so your underground bunker doesn’t flood)

The size and depth of the hole will depend on how many family members are using the underground bunker, but you should aim for a minimum 6×6-foot square or circular space for each person.

After digging, it’s time to pour cement to secure the walls’ stability, and then it should be left alone for at least 48 hours.

Above Ground

While you are waiting for the cement to dry, it’s time to work on building your shelter’s entryway.

Start by covering the surrounding area with plastic sheeting before getting started.

The ceiling should fall about 6-feet under the surface of the ground and should be strong enough to support heavy items like bunk beds.

Dig a trench that leads into your home’s entryway, then use mortar mix (a combination of sand and cement) to create concrete steps leading downward. At this point, you can start building the walls using a cement board.

Finally, cover the ground with a thick, waterproof plastic sheet.

You can then set up wiring for electricity and other amenities such as heaters (if necessary) before installing the door and any other features you want in your underground shelter.


At this point, it’s time to start building the walls of your underground shelter; you should build them at least 12 inches thick.

After this, it’s time for flooring. The simplest option is a single layer of plastic sheeting, but it’s also possible to lay a drainage system using gravel, then cover that with sheeting.


In order to get into your home’s entryway, you’ll need a strong door with at least one deadbolt and no fewer than three hinges.

Installing Ventilation Systems

Now that you have completed these three stages of development, it is time to install your ventilation system before building and installing all necessary features such as electrical wiring.

You should pour a concrete floor into the entryway before starting on the ventilation system itself since this is one of the most important parts of staying alive during an emergency or disaster situation.

The ventilation system will consist of a large PVC pipe extending from an opening near the ceiling and terminating somewhere above ground level.

Make sure that each end of these small pipes is covered with wire mesh before the system is complete; you will need 16-inch openings for them to be effective at removing carbon monoxide, steam, and other deadly gases from your shelter.

If you plan to use a wood stove or furnace instead of a conventional heating system, it is important to make sure that the ventilation system has a direct line to it.

If you are using a gas-powered furnace, this should be hooked up directly to one of the small pipes and wrapped in insulation for maximum safety.

You should also hook up an emergency oxygen tank that can filter out any carbon monoxide that might be in the air.


Here are the step to building your underground bunker;

1.    Location and Safety

2.    Tools and Equipment

3.    The Process

All in all, the best way to ensure safety and survival during a disaster is by having an underground bunker that can serve as a temporary residence.

With the right amount of resources and time, you can create your underground shelter without too much hassle or financial burden.