How to build a snowcave
By Ian Ferguson
Whether you want to claim first tracks at the resort the next day or stay warm on an extended camping trip, building a snow cave can help you stay warm and cozy through cold nights in the mountains.
Snow is a tremendous building material. Once disturbed, it sets up like concrete in a matter of minutes. Because it traps air molecules between ice crystals, it insulates nearly as well as goose down. It can be sculpted with just a shovel, and in the spring near Mt. Baker, it’s (usually) abundant.
Growing up in New England, my brother and I built forts in the snow banks that piled up in our driveway every winter. We envisioned miniature snow mansions complete with slides, escape tunnels, secret entrances, pantries and game rooms. Inevitably, the forts would turn out to be little more than a couple of connecting tunnels, and would usually be destroyed in the ensuing snowball fight.
The idea that digging snow is harder than you might expect is something to consider when thinking about creating your own snow cave. I forgot this small detail when my friends and I skied out from the backcountry lot at Heather Meadows at 3 p.m. in the midst of a blizzard, shovels in hand. Three hours later I was soaked to the bone, shivering and sore, but we had a banger snow cave and we passed the night in relative comfort despite dire conditions outside our home in the snow.
My companions, Kat Thorney and Taylor Riopel Smith, learned how to build snow caves (also known as “quinzees”) from instructors while earning backcountry leadership certifications. I followed their lead, and the results worked out well.
Disclaimer: this article is for inspirational purposes only, and should not be taken as an instructional manual. Surviving a night outdoors in the winter is no joke; it requires proper gear and the knowledge to use it.
How to build a snow cave
• Choose a location well away from any avalanche run-out zones. To do this, imagine a line of sight between yourself and the top of any nearby slope. If the angle between your line of sight and the flat ground beneath your feet (called the “alpha angle”) is 20 degrees or greater, you’re too close to the slope. If you’re not good at judging angles, err on the side of caution and get farther away. If your chosen spot is near trees, make sure there are no dead branches or trees that might fall on your shelter.
• Make a pile. If the snow depth at your chosen site is greater than 6 feet, you can skip this step. Otherwise, create a roughly circular pile of snow at least 6 feet tall with a diameter at least a meter longer than the height of the tallest person in your group.
• Pack it down. Stomp on the pile, hit it with your shovel, roll on it or pat it with your hands. You don’t need to pack the snow very much thanks to the next step, but make sure you’ve hit every area of the pile.
• Wait for at least 20 minutes before digging. Disturbed snow crystals re-bond and harden over time – you’ll be amazed at how even the fluffiest powder firms up after it resettles. Giving the pile 20 minutes to half an hour of settling time ensures that it won’t collapse on you during the digging process.
• Dig your shelter so that the lowest point is the entryway. This might require digging a trench outside your snow pile before beginning to dig into it. When tunneling into the pile, keep in mind that you’re going to have to remove a lot of snow through the entrance hole. We built our entrance hole 4 feet tall and 3 feet wide to minimize crawling during the excavation process. It helps to have one person excavating and everyone else clearing excavated snow in a single-file conveyor system. Once you’ve tunneled in a couple of feet, you can angle the tunnel upward and start to widen out a chamber.
• Be an architect. You can get pretty creative in your chamber design, but keep a few things in mind:
• Cold air settles, so a foot-wide trench angling down from the sleeping area to the entrance hole will do wonders for keeping the space warm.
• Packed snow weighs about 800 pounds (350 kg) per cubic meter, and domes are the strongest structures in nature. Make your ceiling a dome, and smooth it out so it doesn’t drip on you if it starts to melt.
• If you’ll be hanging out in your cave (as opposed to just sleeping), make a space tall enough to comfortably sit up in. We created a “mud room” between our sleeping shelf and our entrance tall enough for standing. It was a convenient place to cook and put gear, but it required a lot of digging.
• Smaller spaces will stay warmer. Try to strike a balance between the structural integrity of your cave, the amount you’re willing to work, how warm you want to be and your tolerance for tight quarters.
• Snow is stronger than you might think, but make sure your walls are thick enough to support your ceiling. You can use the measurements on an avalanche probe to gauge the thickness of your walls and roof. Shoot for about a foot or two of thickness, with walls thicker than the roof. Dig up as high as you want to go before digging out as far as you want to go. If the chamber will be more than six feet wide, consider leaving structural columns of snow to support the roof in the middle.
• Poke ventilation holes. Opinions vary on this front. Our small ventilation holes were promptly covered by falling snow and we had no trouble breathing, but carbon dioxide can collect in a confined space and cause asphyxiation.
• Personalize your space. Sticks poked into walls make great hooks for hanging gear. You can pile snow for shelves or dig out nooks for lanterns or food. If you really want to contain body heat in your cave, you can reseal the entrance hole by stacking blocks of snow, waiting a few minutes for it to harden, then carving out a smaller entrance tunnel, which you can then plug with a backpack. We left our entry hole wide open and our space hovered at a toasty 38 degrees Fahrenheit all night.
• Put down sleeping pads to insulate yourself from the snow while you sleep. It goes without saying, but you’ll need a warm sleeping bag.
• Mark your cave by standing up skis or poles around its
perimeter. This will prevent wayward snowmobilers from running you over in the night – although a well-built quinzee would easily withstand the weight.
Building and sleeping in snow caves can be fun, but it’s not for the claustrophobic. I found out firsthand how nerve wracking it is to lie helpless under literally tons of snow. If the roof of our snow cave had collapsed on us, our chance of survival would have been nil, and that thought made for a troubled night’s sleep. I needn’t have worried – destroying the snow cave in the morning was almost as hard as creating it. No amount of jumping or stomping would budge the thing, and we had to dismantle it chunk by chunk with our shovels. You should always destroy your snow cave to prevent the formation of an air pocket that could collapse under an unsuspecting traveler during the melting season.
Don’t put yourself in a survival situation and expect to build a lifesaving quinzee on your first try. Like other winter camping skills, it requires practice.
Winter camping tips:
- Your body burns a lot of energy when trying to stay warm, so eat a lot of high-calorie food, especially before bed. Fatty nuts such as cashews are great.
- Work slowly so as not to sweat. Wet clothes can quickly lead to hypothermia. In fact, it’s a good idea to bring a complete change of dry clothes – and avoid cotton.
- Down clothing and sleeping bags are warmest, but lose their insulating properties when wet.
- Put boot liners and gloves in the foot of your sleeping bag while you sleep. Your body heat will partially dry them out.
- A bottle of hot water in your sleeping bag can provide up to an hour of extra warmth. x