The Inuit used igloos as temporary shelters during hunting trips. These snow houses can be constructed even at latitudes far from the Arctic regions.
: Select a quarry site When inside the igloo, make sure you have adequate ventilation. Always keep the entrance open.
Step 1: Select a quarry site Select a suitable site for quarrying snow blocks. The snow should be firm enough to cut into blocks, but soft enough to allow the blocks to fuse when pressed together. If the snow is too soft, tramp on it for 15 to 30 minutes, then wait another half hour to let it collect.
TIP: Probe the snow with a pole to make sure the snow in the quarry site formed in one snowfall. Multilayered snow tends to fracture and is unsuitable for building igloos.
Step 2: Dig a trench Use a snow shovel to dig a trench beside the quarrying site. The trench will provide access to the underside of the snow blocks, allowing you to free them as you cut them to size.
Step 3: Start a circular spiral Use the snow saw to cut enough blocks to make a circle on the ground that is the size you want your igloo to be, leaving space for the door. Trim the blocks so that successive block is slightly higher than the preceding one. Smooth the ramp with the snow knife. A spiral ramp should result when you arrange the blocks in the circle.
TIP: The size of your blocks will gradually decrease, but the largest blocks, used at the base, should be rectangular – about 3 feet long, 18 inches high, and 8 inches thick. The blocks will gradually become more and more triangular, rather than rectangular, as you move up the igloo.
Step 4: Make a door Make the door by placing two blocks vertically, facing outward, with a third block on top.
TIP: Place the blocks slightly aslant so that they taper toward the inside of the igloo.
Step 5: Complete the dome Continue adding blocks to form a dome, removing snow build-up from the inside as you work. Add the last few blocks from inside the igloo, leaving a small ventilation hole in the roof.
Step 6: Fill any cracks with snow Fill any open cracks with snow, and smooth the inside of the igloo to prevent dripping.
Step 7: Construct an entry passage Construct an entrance covered with snow blocks. Dig into the snow so that the entry passage is below the level of the igloo's door to prevent heat from escaping.
FACT: Igloos work not by providing heat, but by preserving heat generated by the human body.