How To Build A Tunnel From House To Garage?

There are lots of reasons why you might want to build a tunnel running from your house to your garage. A well constructed tunnel gives you a safe and secret place to hide your loot, to escape, to store necessary items and to be safe from a wide variety of threats. In this article, we discuss what you’ll need to know to successfully dig a tunnel from your house to your garage. Read on to learn more.

Why Would You Need A Tunnel?

There are a number of reasons why you might want to have a tunnel running from your house to your garage.

For one thing, if you live in an area where you get a lot of snow or where it is punishingly hot, having a tunnel that keeps you from having to go outside when you need to travel to and from the garage can be extremely helpful.

Additionally, a tunnel can provide you with a quick, safe means of escape in the event of home invasions or disasters such as hurricanes, tornadoes and fire.

Take Tunnel Construction Seriously

Digging a tunnel is a serious matter. Even if you’re just digging a small tunnel for fun, it could collapse on you and kill you. That’s why it’s very important that you follow all necessary safety steps when digging a tunnel from your home to your garage as an escape route or safe space.

There are a few things you’ll need to determine before you ever put the shovel in the ground. First of all, make sure that you have the mineral rights on your property. If you don’t, you could find yourself in violation of the law.

Be sure to consult your local building authority to make sure that you are within code. Double check all local building codes to make sure you’re in compliance when building subterranean walls.

Building a substandard tunnel is not just undesirable, it can be downright dangerous. Your tunnel will have to hold back many tons of dirt and rock, so you must take its construction very seriously.

Next, be sure to have your local utility providers come out and mark any underground lines. Taking these two steps can save you from lawsuits and actual, physical disasters.

Don’t take any shortcuts. Be sure to have an expert evaluate your soil to make sure that it is stable enough to dig a tunnel. Other conditions that might get in the way of digging a successful tunnel include outcroppings of granite or other rock or heavy clay soil that makes digging extremely difficult.

You’ll also have to take into account problems such as high water tables. If you neglect this information and your tunnel fills up with water while you are building it or when you try to use it, you can very well drown.

Once you’ve determined that the soil in your yard can support a tunnel and that you will not be digging through any utilities or violating any laws or codes, you can start planning your tunnel.

Work With An Engineer

Understand that you will need to dig your tunnel and brace up floors, sides and the roof in order to create a truly safe tunnel. A qualified engineer can help you make safe plans for doing just this.

You might think that you could simply lay a series of shipping containers in your excavation or use some culvert piping to create your tunnel; however, this would be a bad mistake. The metal used in building shipping containers and culert piping is not really strong enough to hold back the weight and pressure caused by dirt.

It’s important to build a sturdy framework which will securely hold your tunnel in place. You’ll need a certain number of supports depending upon the length and depth your tunnel.

If you feel that your tunnel needs extra support, it’s a good idea to use galvanized steel pipes or, if you prefer to use wood, 2 X 12 beams can be effective.

Backyard Tunnel Construction

Can You Dig An Escape Tunnel By Yourself?

You must make sure that you are physically up to the task and that the area where you will be working is conducive to digging a good tunnel. If you are not fit enough to perform the job and/or the soil is not of the consistency that can be easily worked with, you may very well experience a cave-in which could seriously injure or kill you.

In most cases, you are much wiser to hire a professional engineer rather than setting out to perform this project on your own. A lot more goes into creating a safe and useful tunnel than simply digging.

Once you have determined all of the factors that are pertinent to your plan and have roughly outlined the plan on the surface of your yard, you need to make a proper blueprint.

An engineer can help you draw up a blueprint that takes all factors into account, as well as making sure your tunnel is in accord with all local ordinances. Your engineer should also secure any permits you may need.

How Will You Dig Your Tunnel?

Sorting out the engineering is the most important step in creating a safe escape route. With this done, you need to determine how you will dig your tunnel.

You could work entirely underground using a process known as boring, or you could use the cut-and-cover method, which involves digging a big, open ditch and then building a roof over it which you will cover soil.

Naturally, there are pros and cons to both methods of tunnel digging.

If you decide to use an open trench method of excavation, you can use a backhoe to dig your trench. This makes quick work of it. If you work with a backhoe, you may be able to get your tunnel entirely dug in a day or so.

With this sort of open tunnel construction, once you’ve dug the tunnel installed the flooring and braced up the walls, you’ll need to put on some very sturdy roofing. When you put on the roofing, remember to install vents for excellent air circulation.

If you want to keep your tunnel secret, you’ll naturally want to work entirely underground. The downside of this is that you are much more likely to become subject to a cave in.

If you decide to work entirely underground, you can dig the old-fashioned way with picks and shovels, or you can rent or purchase a boring machine which will allow you to work underground a bit more quickly and easily. Even so, this type of excavation is very difficult and takes a great deal of time.

If you’re digging underground, it is naturally best to work in small increments. Each time that you have completed digging on a section that is between 2 and 4 feet long, you should stop and brace it up. Doing so will help keep your worksite safe, and gives you a break from the arduous, backbreaking labor of digging by hand.

If you’ll be working entirely underground, you’ll also need to install lighting as you go along. You cannot rely on flashlights or on fuel-burning torches and lanterns as a means of lighting your tunnel. To do so exposes you to great danger.

If your flashlight gets broken or the batteries die, you’ll find yourself plunged into darkness. If the flame from a fuel-burning source of light gets away from you, you could find yourself trapped underground by fire.

Even without this, keep in mind that flames need oxygen and so do you. You don’t want to have to compete with the light source in order to breathe. In fact, throughout the building process and afterward, you must make good air circulation a top priority in your tunnel.

If you don’t include good ventilation in your tunnel, you and your family members could very well suffocate when trying to escape an emergency.

When you plan your tunnel, you must be sure to include plans for good air circulation. If air is not able to circulate through your tunnel on a regular, ongoing basis, mold may develop. This can be a very serious health hazard.

What Can You Do With The Dirt From the Tunnel?

You’re going to have mountains of dirt to dispose of. You may need to haul it off to the dump, or you may be able to pile it up in a discreet location on your property for use around your yard and garden.

You may have seen a few comical (yet true) methods of dealing with excess dirt in old movies. For example, if you are trying to keep your tunnel a secret, you might carry hidden dirt receptacles in your pants legs and then empty them gradually when you walk about above ground. This method has been featured in many prison movies.

Plan Your Entrance & Exit

Whether you use open trench or underground construction, once your tunnel is complete, you’ll want to pay attention to detail in the finishing touches. For example, your doors should be top quality. Even though the entrances and exits of your tunnel will be underground, you will need to have some heavy duty, sealable, lockable doors in place.

When you plan your trap door leading into your garage, you must take careful account of where you store items and where you park your car. You don’t want to find yourself rushing through your tunnel, hoping to enter your garage only to find that you can’t open the door because your car is parked on top of it.

Make Your Tunnel Multipurpose

As long as you’re digging a tunnel, you might as well add some extras to help make it more useful. For example, you could keep your emergency or “bug-out” bags in your tunnel. This will make it quick and easy to escape from your house grab what you need and rush to safety.

Keep in mind that it’s a good idea to store your emergency supply bags near the exit of the tunnel so that you don’t have to grab them first thing and carry them as you rush through the tunnel.

Make your tunnel as wide as you can. There’s no point in making it so narrow that it will be difficult to pass through quickly and easily, and having a wider tunnel makes it possible to do things like store some extra food, turn about in the tunnel if you need to and so forth.

You don’t want to have to crouch as you rushing through your tunnel, and you don’t want to be a tight squeeze. Be sure that you have enough room in your tunnel that you can stand up, sit down, turn around and perhaps carry someone who is injured if you must.

You may want to be able to use your tunnel as a safe room in case of natural disasters or unrest. For this reason, you should be able to put some storage shelves and other necessary items in the tunnel.

You want the quality of air in your tunnel to be healthy. Your tunnel should be like a basement or root cellar, dark, dry, cool and secure. With these conditions, you can store nonperishable food items, batteries and fuel. Don’t forget to store some containers of drinkable water. Keeping a porta potty in your tunnel is a good idea.

A well constructed tunnel can act as a climate controlled root cellar, tornado shelter or bunker. In fact, you may even want to dig a room off the side of the tunnel for this sort of use.

Building A Tunnel Is Hard Work, And It’s Not Cheap

These are actually reasons why you should do everything you can to make your tunnel as well constructed as and as functional as possible. It really won’t cost you a whole lot more to do a good job than to do a slipshod job.

A correctly engineered and properly constructed tunnel is a permanent addition to your property. It will give you a safe way to escape a wide range of problems such as home invasion, hurricanes, tornadoes, fire and more.

Be sure to plan carefully, build wisely and add in extra features so that you will have everything you need in a well constructed and useful tunnel.

For more garage DIY ideas, you can check our guide to building a laundry room in your garage, this one about swing out doors, or the following one about building a breezeway.

Resource:

1. https://www.osha.gov/sites/default/files/publications/osha3115.pdf