How to build a survival shelter when lost on a hike

Why build a survival shelter?

I’ve been reading a lot of reports lately about day hikers who have been forced to spend a night, or multiple nights, in the bush. The circumstances varied but as day hikers, they were often not prepared for the overnight stay, sometimes in cold and wet weather.  I find it interesting that a lot of these articles focus on how much food people survived on; ‘Lost skier survived on Mars bar and snow‘. ‘Hiker lived off one caterpillar and two chocolate bars‘. ‘Bushwalker drank muddy water and ate plants and flowers to sustain himself‘. Rarely do these articles focus on how they survived by seeking or building a shelter.

When lost in the bush, most people panic through fear they will run out of food. Did you know you can survive three weeks without food provided you have water and shelter? Knowing how to construct a survival shelter is an important skill.

Survival Rule of Threes and survival priorities

If you are in a survival situation, remember and prioritise by the four levels of the Survival Rule of threes:

• You can survive for 3 Minutes without air (oxygen) or in icy water
• You can survive for 3 Hours without shelter in a harsh environment (unless in icy water)
• You can survive for 3 Days without water (if sheltered from a harsh environment)
• You can survive for 3 Weeks without food (if you have water and shelter)

The main point of the Rule of three is that we have to focus on the most immediate problem first. If the weather is warm, you will need to focus on finding water as your priority, food and shelter building can wait. There is no need to think about food or water if you are cold and wet as hypothermia presents the greatest threat to your survival. Make no mistake, if you are shivering and can’t get dry and warm, you may not able to function after three hours. If you are alone, you may have only about three hours to live.

Unfortunately, some hikes don’t go according to plan, even day hikes. You or a member of your group may become ill or injured and can no longer continue. You might be disorientated, lost or underestimated the time the hike would take. These situations may force you to spend an unexpected night or more in the elements so you can resume the next day or wait for emergency extraction. Keeping warm is essential and knowing how to build a shelter is an important survival skill to learn.

What is a survival shelter?

A survival shelter is any structure (naturally occurring or man-made) that can protect you from animals, insects, and the elements. Survival shelters can include caves, fallen trees, dugouts, tunnels, debris huts, lean-to’s and more advanced structures. Shelters come in many forms and serve a variety of purposes, but one thing is certain: knowing how to quickly build one, can and does saves lives.

Fortunately, whether you’re in the bush, snow, or even in a desert, building a survival shelter out of natural materials is a relatively simple process.

Important note:  You will need a build a shelter suited to the weather conditions. Lean-to shelters are better suited to warm environments, A-frame shelters are better suited to cold environments. In a cold environment, you need to enclose yourself in your shelter as much as possible to protect you from the elements as cold environments are where you are more likely to become Hypothermic. For this reason, this article is focused around a A-frame debris shelters.

Take adequate clothing

Your first line of defense against the elements is the ‘shelter’ you choose to wear or carry in your pack. It might be beautiful sunny weather for your day hike but nights can be bitterly cold. If all you are wearing are short and a shirt and are forced to stay out over night, hypothermia becomes a very real threat. Be prepared is my advice. If you wear layers of synthetic material or wool, and carry a shell of windproof, waterproof material, your changes of survival will be greatly improved. Trapping body heat instead rather than expending it. Carrying a lightweight tarp or bivvy is also a great idea.

Types of survival shelters

Deciding what type of shelter is important part of survival in the wilderness.  If you know a few shelter designs and know what they are best suited for, then you will be able to make the right choice.

• Tarp: Lean-to shelter: For this type of shelter, you just need a lightweight tarp and some cordage. You can even make it with a rain poncho if you have one. Simply tie each end of the tarp to a tree. This style of shelter is not particularly warm and may not keep wet weather off you as it is generally open on three sides.
• Tarp: A-Frame shelter: This is an A-frame style shelter. Tie some cordage between two trees and drape your tarp over it. Then use some rocks, sticks or more cordage to anchor the sides of the tarp away from you. You could even use a horizontal branch, log, large rocks, anything that will allow you to create cover under your tarp. This style of shelter provides better protection from the elements than a lean-to shelter as it is only open on two sides.
• Cocoon shelter: This style of shelter is basically a pile of leaves or debris without any framework. If it’s almost dark and you don’t have time for other shelter building, quickly collect dry debris (leaves, bark, grasses), make a pile around 1m high and slight longer than your height. Burrow into the centre of pile so you have debris insulating you from the ground and the elements. This style of shelter is basic but act as a natural sleeping bag that protects against heat loss.
• Debris shelter: Fallen Tree: This is my favorite as it doesn’t expend a lot of energy to build. A fallen tree can be easily adapted to the situation. It does rely on you being able to find a fallen branch or tree that has enough room under it for you to crawl in. You can adapt the tree in many ways; drape a tarp over the limb to form a tarp tent, lean branches and debris against the fallen limb to act as your shelter wall. If it is cold and windy you can completely enclose yourself by using additional debris to block off the entrance. A fallen tree shelter is a similar structure to an A-frame shelter and will help trap your body heat inside.
• Debris shelter: Lean-to: A lean-to shelter is simple to make and can be built to accommodate larger groups. The lean-to is open on three sides so doesn’t trap body heat as well as an a-frame or completely enclosed shelter.  You can pile additional debris against the sides so for extra protection if you have time. A lean-to shelter can be build between trees, against rock walls, overhangs or embankments. One advantage of this style of shelter is by building a fire in front of the shelter, the rear wall acts as a heat reflector to help keep you warm. For additional radiant heat, you could also build a small wall or pile rocks on the other side of your fire.
• Debris shelter: A-Frame Shelter: If you can’t make a lean-to, you can make an A-frame shelter. If built properly it can keep you warm and dry through adverse weather. The A-frame shelter can be built out of branches and debris. It can also be built using a tarp or poncho as mentioned earlier. Most survival (mylar emergency) blankets are too small to build a proper A-frame.
• Snow shelter (cave): Building snow shelters is a complex subject which I dare not tackle due to lack of knowledge in this area. There are complete books written on this subject if you are interested in learning more.
• Dugout (pit) shelter: Dugout shelters provide great protection from wild animals, they also naturally stabilise heat, providing you with great protection from the elements. A dugout shelter will take considerable time to excavate an construct so there’s probably no point providing more info about this style of shelter for overnight situations.

Following is on overview of how to build an A-frame debris shelter due to the protection from the elements this style of shelter provides. The fallen tree style is my favourite but you can’t always be sure you’ll find one. The lean-to is possibly the easiest but doesn’t provide as much protection. The principles explained below can be applied to any type of debris shelter.

A-frame Debris Shelter

A debris shelter is a simple shelter you can construct from natural materials.  It does not require special tools or equipment to construct.  This style of shelter provides protection from the elements and is relatively quick to build, although you will expend a lot of energy doing so.  The main feature of this style of shelter is it works without the need for fire to keep warm. the insulation from debris, traps your body heat inside.

Debris shelters can be used effectively in a most environments, provided you have debris.  Building this style of shelter in an alpine environment, above the tree line, may be a challenge due to the lack of debris.

Practice building a debris hut to develop this important skill.  It’s perfectly acceptable to cut down live trees in a survival station but if you are practicing in the bush, be sure to use only dead materials. If you build a debris shelter, or any kind of shelter in the bush, deconstruct the shelter when you are done.  Return the area to its natural condition.

How a debris shelter works

The debris shelter works by insulating you from the elements using thick layers of natural material.  These layers of material will help shed rain block wind and will trap your body heat inside.  The debris provides a pocket of air inside the shelter that is warmed by your body heat.  For this reason debris shelters should be built as small as possible.  Think of it as a natural sleeping bag. You want your body to heat only the space required to keep you warm.  If the shelter is too large, you will be cold because your body is unable to warm the large volume of air. If you are with a group, make the shelter large enough to just fit everyone inside and forget about invading other peoples personal space. This is a survival situation and body heat from others will keep you alive.

When to start to building your shelter is important.  Don’t wait around until it gets dark before planning your shelter. Begin work on it the moment you decide you have to spend the night outdoors.  A debris shelter, depending on the size you need and availability of material, can take two to three hours to construct.

The best place for your shelter

Choosing the best place to build a survival shelter is important. It should be in the driest spot you can find. Nothing sucks out body heat faster than wetness. Rain and moisture are often your deadliest enemy. When you’re wet, it’s extremely difficult to stay warm. This is one of many reasons it’s important to make sure your shelter is waterproof and dry.

You might be lucky enough to find natural coverage and protection from the rain. Large trees, fallen limbs and caves can be a lifesaver if you don’t have the natural resources or time to build your own shelter. Looking for a natural shelter is always your best option as it saves time and expends far less energy.

It is important to build the shelter near natural construction materials.  You don’t want to walk a great distance to find materials and have to carry them back for your shelter.  This expends too much energy and increases construction time dramatically. Be wary of large tree limbs on the ground though and try to determine if the trees overhead are likely to drop their branches. Locate your shelter away from game trails.  You don’t want animals visiting your shelter at night, unless you are starving of course.

If it isn’t too cold, build a lean-to shelter on high ground. A breeze will help keep the bugs away, and you’ll be easier to see if a search party passes nearby. If a cold wind is blowing, choose a spot sheltered by trees. But don’t build in the bottom of deep valleys or ravines where cold air settles at night.

Check what the direction the wind is blowing. You don’t want to build a shelter that’s open to the wind. Even if the wind is not blowing now, it could pick up during the night. The easiest way to check the wind’s direction is to simply try to feel it. If you can’t feel the wind, look for natural signs such as moving trees, swaying grass or clouds.

You should try to elevate your bed off the ground if possibly. This is it an important part of staying dry, and helps keep bugs and critters out of your bed. Elevating doesn’t always mean building a high platform, you could lay some logs down first and lay your bedding material (moss, leaves etc.) on top of them.

Me and a few mates practicing our lean-to building skills

What are your shelter needs?

• How many people are in your group? If you have time and your group is large, you may need to build a few shelters
• How cold is it? Do you need a shelter at all?
• Is it likely to rain at night? Can you find enough debris to keep wet weather out?
• How much time do you have to build the shelter? If it is getting late and the sun is already setting, you may not have time to build a shelter so should look for a natural shelter instead.

Building an A-frame Debris Shelter

Once you have selected a good site, you can start working on the debris shelter’s frame. Made entirely out of sticks, the frame requires no lashing and is shaped like a long-sided, sloping pyramid with a triangular opening on the high side. First, you will need to find a long sturdy stick for the ridgepole. The ridgepole is the backbone of the shelter. It should be straight and around half a metre taller than you. Try and find one that is around 75-125mm in diameter and is not rotten, you don’t want it to collapse under the weight of debris.

Building the frame

Next, find two forked, Y-shaped sticks about waist height. Put the forked ends of the ‘Y’ sticks together and the straight ends on the ground to form a triangle. Fit the end of the ridgepole into the forks of the sticks so that you have a long-sided, sloping pyramid with a triangular opening at the front. Push down gently on the junction of your frame to check it is stable. Check to see if your frame is the right size by lying underneath the ridgepole with your feet at the low end. You should be able to lie under the ridgepole on your back with your head behind the entrance and your toes underneath the ridgepole. If it fits, continue by building the shelter walls. It’s a good idea to place the unsupported end of the ridge pole on a large rock or another small log.  This creates more volume in the shelter.  If the end of the pole rests on the ground, the space at the end of the shelter may be too low for your feet.  Make sure the pole and rock are stable so the ridge pole doesn’t fall later in construction.

Another method of supporting the ridgepole is to place it in the crook of a tree.  The advantage of this is it does not require cordage, the need to tie a lashing or find the additional Y-shaped sticks.  It is also simple and easy.  Depending on the width of the tree’s trunk, you may have to relocate the door from the end of the shelter to the side of the shelter so you can gain access.

Building the walls

The walls of the debris shelter are constructed using rows of sticks called ribs. The ribs should be close together and lean against the ridgepole, following the same angle of the ‘Y’ sticks to the ground. Make the angle wide enough so you can comfortably fit inside. The ribs should extend no more than 10mm beyond the top of the ridgepole. If they are too long, this will encourage rain to travel into your shelter and onto your face.

After the ribs are in place, lay smaller branches (twigs) across the ribs to form a framework/lattice.  The twigs should span the gaps between the ribs.  Start at ground level and rest the bottoms of the twigs on the ground.  Then place the next layer higher up on the structure and let gravity hold the twigs in place. It helps to weave some of the branches through the ribs to secure them in place. Don’t add any debris to the walls yet.

Making your bed

Fill the inside of the shelter with dry insulating materials. Don’t just put it on the ground as a mattress, completely fill it if you have enough material. Leafy materials such as dead leaves, bark, and grasses are ideal. The material you use needs to be dry and as light and ‘fluffy’ as possible to help trap air inside. This improves the insulating qualities and acts as a blanket, trapping warm air against your body. Don’t use any green material on the inside of your shelter, however, as the moisture inside of it will let the cold creep into your bones. When you enter the shelter, insert yourself into the middle of the insulation.  The material below insulates your body from the ground.  The material above insulates you from the air. If the ground is damp, it is a good idea to lay some thicker sticks on the ground first to keep the leafy material out of the wet.

If it is not going to be cold at night, you won’t need as much leafy material so use your judgement before starting to collect what you need.

Insulating your shelter

The outer layer of material insulates the shelter from the elements.  It consists of dry dead leaves, bark, and grasses, piled onto the lattice. It doesn’t have to look pretty.

Don’t skimp on materials.  You may feel tired at this point but when you sleep in a natural shelter, it will protect you or it won’t.  Keep piling on the material until it is at least 30mmm (30cm) thick. 500mm thick is even better. Just keep piling it on.

Find a handful of medium sized branches and gently lay this over the leafy material.  This will keep the insulation on the shelter during high winds.  Adding the branches effectively keeps the roof from blowing off your shelter during the night.

Building a door

The final step of your shelter build is to construct a door. This may seem unnecessary but without a solid door, all your insulation is useless. The door is the plug that keeps all the heat inside. The simplest technique is to simply pull a large pile of debris into the shelter after you crawl inside. With enough debris, the leaf pile will completely fill the entrance, keeping you comfortable all night. If you want, you can also sandwich a thick layer of debris between vines or twigs woven into two flat panels to use as a door.

If you have used a large tree to support your ridge pole, your doorway may be a side entrance.  The same steps apply in making the door.  But you must ensure that all of the insulation above the door remains in place when you enter and leave the shelter.

Practice, practice, practice

Making a fully functional debris shelter takes practice. Until you have built one and slept in it on a cold night with no blanket, it is hard to appreciate the sheer volume of debris needed to stay warm. It is also an amazing experience to pass the night warm and comfortable in a shelter made from nothing but your hands and the raw materials that you find in the bush. As mentioned earlier, if you build a debris shelter, or any kind of shelter in the bush, deconstruct the shelter when you are done.  Return the area to its natural condition.

Make sure you are visible

Debris shelters are made of natural materials so they blend into the environment really well. As your debris shelter is as an emergency shelter, you want to make sure you are still visible to search and rescue teams.  Keep this in mind and consider hanging something bright outside the shelter to attract the attention of rescuers. A pack cover tied to your shelter, your backpack left outside, a giant arrow on the ground made from branches, anything that attracts attention.

This applies for all emergency survival shelters, whether it be a cave, overhang, or debris shelter. Be creative but make sure you will be noticed.

Tips

• Before adding your leaves to the shelter, sift through them to check for bugs.
• While leaves can work on a lean-to, a tarp is a better insulator if you have one. You’re less likely to be exposed to bugs this way too.
• While tools are useful, if they are not readily available, improvise with things like sharp rocks.
• Knives and machetes are useful but dangerous if mishandled. Never use dull tools. Don’t use tools in a manner they were not intended for. Serious injury or death can occur from misuse of tools.
• If you intend to cut down a tree be aware of what is around it. Extreme injury or death can occur from negligence.
• It’s perfectly acceptable to cut down live trees in a survival station but if you are practicing in the bush, be sure to use only dead materials.
• Leave No Trace: If you build a debris shelter, or any kind of shelter in the bush, deconstruct the shelter when you are done.  Return the area to its natural condition.

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Image attribution: Walterpeitz, CC BY-SA 4.0, via Wikimedia Commons