Snow Cave — The lighter the snow shovel, the more snow you can throw before you get tired.
To start, mark out a circle that is the size of the outside of your snow cave wall. For two adults you will want about a 10 ft. circle (5 foot radius). A 10 ft. outside circle will create a 6×6 ft. interior.
For more than two people, just add 2 feet to the diameter for each adult (i.e. 3 people = 12 ft, 4 people = 14 ft). If your snow cave will be wider than 16 feet in diameter then consider stretching it out instead of making it round.
A stretched-out shape is stronger and safer than a wide dome. If you have 6 people, make your stretched snow cave 12 ft. wide and 20 ft. long. For each additional person add 2-3 feet depending on how comfortable you want to be (i.e. 7 people = 12×23, 8 people = 12×26).
The stretched-out shape is best used if you leave room for an isle along the wall so every person has access to the door.
Once you have determined the size, dig out the outline of the snow cave and work in a spiral while throwing the snow onto the pile. If the snow you want to throw is too far from the pile, you can use a tarp to drag the snow to the pile.
If you don’t have a tarp, you can also double throw the snow; first in a temporary pile closer to the snow cave and then from the temporary pile onto the snow cave. Your pile should naturally be an even dome shape when finished.
Your snow pile will shrink and settle 6 to 12 inches during the night so you should pile about 2 feet higher than you want the inside height to be.
We like our snow caves (and our tents) tall enough to stand up in so they are usually 8 or 9 feet high on the outside. If there is not a lot of snow in your area, make sure it is at least 5 feet high. Plan on at least 4 hours (5-6 if it is tall) of hard labor to finish the snow pile.
After you pile the snow, let it sit for at least 2 hours. This will give the walls and ceiling a chance to set and harden, which will help prevent collapsing.
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