I have built a multitude of debris shelters in the three decades of my wilderness living experience and they have their place, but in truth, they are just about useless outside of very specific situations. First, let us cover what the standard debris shelter consists of and their practical uses. Then we will cover their downfalls and lastly, ways to make them far more functional.
The standard method in building a debris shelter is to build a basic frame, here in the States we tend to use a wickiup style. Over the frame we either lay or weave in thinner sticks to form a mesh to lay the debris over. In a coniferous forest, we might forego this step and directly weave in boughs with foliage still attached and call the shelter complete.
In broad-leafed forests, such as where I live, the incorporating of the thinner branches is a must before the leaf litter is applied. Another popular material in certain areas is moss. If this is utilized, be sure to collect it down to the soil it's attached to for the best results. A combination of any of these can be used as well.
After at least a two foot thick (.6m) of debris is applied to the frame, another round of branches or poles is then laid over the debris to hold it all in place. Without this final layer of poles, the wind will strip your shelter bare and you'll find yourself sheltering under a naked frame. The below example will not hold up. Look at the peak, it makes this shelter just about useless.
The issue with all these debris shelters is that in the rain, even light rain, they will eventually leak. In a heavy rain it'll be almost immediate, especially at the peak where the debris is the thinnest. Even in snow you're bound to get leaks. If the shelter has an internal fire or if a great deal of heat from an exterior fire is reflected inwards, the heat will travel upwards through the debris, melt the first layer if snow and drip, drip, drip. A true debris shelter is useful only in dry weather when looking to get out of the cold or if it is snowing, you're not concerned with using fire to keep warm.
Now let's look at ways to make the debris shelter function in wet weather, for what good is a shelter than can be used only in ideal circumstances? The most simple solution for the modern woodsman is to bring some form of man-made waterproof membrane. Begin the shelter in the same manner as before, build the frame, fill any gaps with more poles and begin covering it with debris. If you lay the membrane directly over the frame, it is likely to get punctures from the poles or branches.
Having a thick first layer of debris not only protects the membrane, it also insulates far better than having the debris solely on the outside of the membrane. Make this layer at least 1" (.3m) thick at the very minimum, more the colder it is. It's impossible to overdue the amount of debris on the inner layer as long as the membrane still fits. If it is a tipi or wickiup style frame meant to have an internal fire, wrap the membrane around the frame leaving it open enough at the top for a smoke hole. Make sure to secure it at the top around the smoke hole.
In any shelter where you have an internal fire, always make an air intake that feeds to outside the shelter. If not, you will end up with a very low smoke ceiling and possibly a life-threatening situation. If the frame is a lean-to or A-frame, lay the membrane over the entirety of the shelter. It should extend all the way down to the drainage ditch encircling the shelter. If it falls short, rain will penetrate at the base of the shelter. Every shelter needs a drainage ditch, even a tent with a sewn floor.
After the membrane is in place, cover it again with another thick layer of debris before you lay the outer layer of poles. This will keep the poles from wearing or puncturing holes in the membrane just like the first layer. I can't reiterate enough the importance of the outer layer of poles. They don't need to be thick, just heavy enough not to be disturbed by strong wind, and close enough together to hold everything in place. Ideally the poles are laid touching side-by-side.
In truth, this is not a true debris shelter, it's a naturally insulated tarp shelter. If you use a treated canvas, you can feel no guilt if you have to abandon the area before you remove the man-made material. It will return to the Earth in a reasonable amount of time. Artificial materials will last much longer but are a pollutant and should never be left in the forest if no longer in use. This is why I prefer using solely natural materials, you never know what life might throw at you.
My specialty is building permanent shelters from solely what is on site. To do this in the style of a debris shelter, and it function in all manner of weather, is truly impossible. To make a completely natural permanent shelter you need to cover it with thatch, hides, stone, wood, bark or earth. In my next post I'll be covering the basic construction of, in my opinion, the pinnacle of forest shelters, the earth shelter.