Years ago, after a long night of acting like a 24 year-old in Chicago, I was tricked by a lawyer into helping our mutual friend move during the winter. While many hilarious things happened that weekend, I remember it most vividly as the first time I saw an igloo. A real igloo like in a cartoon.

It was in the tiny back yard of the walkup we were moving into, and it was the first thing we noticed when unloading the U-Haul. We stopped and stood around it asking each other questions. Who built it? Where did the idea come from? How did the roof work? Was it warm? Later, we would speculate on what our future wives would be like, as young men do, and hope we found partners who would be as interested in igloos as we were.

On 1/13/2011, a blizzard hit Boston and dropped almost a foot of snow on the ground. My office was closed for the day, giving me the first snow day I’d had in years. My friend Jim texted me to see if I had any good ideas for how to spend the day. “We’re building an igloo” I wrote back. And it began.

Without any research or preparation, we trudged out into the mushy gray urban snow and picked up some cardboard boxes from the local grocery store. We headed out to a nearby park and started construction without any real plan. I’d tried to build one years before and failed miserably (I blame the snow quality).

Laying the foundation

We cleared a ring in the park and began making bricks by packing snow into the cardboard boxes. We noticed each successive layer of bricks compacted the lower levels, turning them into a solid ice-like wall. During construction we bumped the walls several times, noticing the increasing toughness throughout the day. Working with freshly fallen snow was definitely a big help.

After setting the foundation down, most of the discussion was focused on the curvature of the wall and forming the roof,  the most difficult part of the construction. The roof was also the most popular topic of discussion for passers-by, who posed for pictures in front of it and told us how awesome it was. We also began building an archway entrance and planned on adding a keystone to hold the arch at about 4 feet off of the ground. This part did not work out well.

It turns out architects since the beginning of time had been using the concept of an inverted caternary arch (Wikipedia) in building construction. A caternary is basically a parabola-shape where the bricks all lean against one another and somehow the whole thing stays up. In an igloo, the bricks successively bend more and each ring holds up the one above it (in theory).

Walls beginning to curve in

We stacked successive bricks closer to the center and got the walls to bend somewhat. The right side curved too quickly and collapsed a few times in the process. After about 5 hours of work, we called it a night when we finally managed to close the archway and get a few more bricks onto the top layer. The roof ended up with a sizeable hole and we felt it was incomplete, but then again we were exhausted.

Roof viewed from below

After breaking for dinner, we returned to the site and found someone’s spraypainted graffiti tag inside. I would have preferred something more imaginative than random letters, but it gave the igloo some character.

Here are some pics of the final construction – it’s not bad for a first try and we definitely learned some ways we can improve the process. For one thing, we could have bought a contraption that helps build perfectly-sized bricks in half the time (link).

The front view

The side view

The final structure was not perfect (like this one) but we were pleased with the result. It was quiet and somewhat warm inside, but more importantly, it was fun to build. I hope it survives for a few days.