Snow shelters

Snow shelter are a great way to avoid carrying a tent in the winter. When built properly, they can be very comfortable, especially when the temperature is well below freezing. There are 3 basic kinds of snow shelters: snow caves, quinzhees and igloos. Also, hybrid snow shelters can be built that incorporate other equipment. The simplest of these is building a snow wall around your camp to keep out the wind. There are many configuartions possible that use tarps as the roof and snow as the side walls.

Snow Caves

Snow caves are the easiest and fastest to build snow shelter, but a healthy snow pack is required. 2m of snow is a good starting point, the more the better. A couple good shovels and probe are the only tools needed. Make sure to probe your potential snowcave site before digging to discover any rocks, stumps, ice layers, or crevasses that might be hidden under the snow.

Snow caves are easiest to dig if you start on gentle slope. You can dig into the slope, instead of down, which make getting in and out easier. The slope makes it easier to clear the excavated snow away from the entrance. Don't pick a slope that's too steep, or else you will have to put a 90 degree turn in the cave. Digging into a slope also make it easier to construct a heat trap - read more on this later.

A good sized snowcave fits 2-4 people. Any larger and construction becomes a difficult and long process. There absolutely must be enough headroom to sit up inside without touching the ceiling, or you will be in for an uncomfortable morning. It's best to dig the ceiling into a high arch. This keeps the cave from sagging too much overnight. Don't go oveboard though - keep the thinnest part at least 30cm thick,. Wide, low caves are the worst, and you will wake up with the ceiling 2 inches from your face.

A good tactic for cold weather is to construct a heat trap. To do this, the floor of the sleeping area should be higher than the ceiling of the entrance, thus preventing cold air from flowing into the sleeping area from outside. A heat trap is easiest to build if your snowcave is dug into a slope, as it is very natural to dig somewhat upwards when excavating the entranceway.

Quinzhees

Quinzhees are a Snowcave-igloo hybrid for shallower snowpacks. Snow is piled up to a suitable height, packed, and then dug out from the inside like a snowcave. Quinzhees are much easier to build than igloos, but take a lot more time than a snowcave because of the time required to make the mound. One trick to speed up the mounding process is to pile up all your gear, and then pile snow onto the gear. The gear can then be retrieved during the excavation. Be careful what you use for this, especially if the snow is wet.

Igloos

Igloos are the mediterranean villas of snow shelters. They are roomy, confortable, and let in a remarkable amount of light. They are also notoriously difficult to construct compared to other snow shelters, and require you to have a snow saw in addition to the usual equipment.

To start, a quarry must be packed out. The colder the snow, the more difficult this will be. The quarry needs to be vigourously ski packed (jumping preferred) and then boot packed (again, jumping preffered at the end) and the left to freeze up solid for a few hours. Blocks must be cut from the quarry with a saw in order to get them uniform. All blocks must be nearly exactly the same size. 6"x12"x18" is about right. They can be thicker at the base of the igloo, and thinner near the top, but all block should be square, no tapered.

The idea igloos is a perfect hemispherical dome. To keep on target throughout construction, use a ski pole or a stick or something to measure from the centre of the igloo. Start the igloo by drawing a circle in the snow using the measuring device. Make it big enough for everyone to fit that needs to fit. A 4 person igloo is a good size, and not too hard to build. The first few blocks must be cut off at an angle to make a ramp. If you want to get fancy, the entire first row can be a continuous ramp. The first row of blocks should lean in to the centre only very slightly.

Build the igloo in a continuous spiral, keeping one person on the inside. Each new block in the spiral is supported by the previous one. This gets very tedious towards the top of the igloo. Each block must be held in place and allowed to sinter (stick) to adjacent blocks. Block corners can be trimmed with a saw to maximize contact with adjacent blocks. Finally, cut a cap to match the size of the remaining hole. The middle person is critical for lowering the cap into place.

Note that at this point, the middle person will be built into the igloo. Now is the time to cut out the door. Just cut a nice arch shaped hole into the igloo wall.