Coloured Ice Block Fort in Dryden, Ontario: How Chris Marchand Built It

In January 2014 Chris Marchand of Dryden, Ontario, turned one of the coldest winters in years into a party venue: an 8-by-8-metre backyard fort built from about 400 coloured ice blocks. He posted the build on Reddit under the name UnspeakableFilth, and within about 12 hours the photos had passed 700,000 views.

A Dryden backyard and a month of deep cold

Dryden is a small city of about 7,400 people on Wabigoon Lake in the Kenora District of Northwestern Ontario, on the Trans-Canada Highway between Winnipeg and Thunder Bay. Winters are long and hard: January averages a high of −11.6 °C and a low of −21.9 °C, and the record low is −46 °C.

The winter of 2013–14 was colder still. For about a month, daytime highs stayed at −25 °C or below, and Marchand built at night in temperatures between −28 and −35 °C. Perfect conditions, in other words, for freezing water.

How he made the coloured ice blocks

The method was simple and relentless. Marchand carried water from his kitchen sink to the deck, filled plastic containers holding about eight litres each, added food colouring to some of them and left them outside to freeze. At his peak he was turning out around 30 blocks a day, and he kept it up for a full month until a colourful stockpile filled the yard and the neighbours started to stare.

His inspiration was the rainbow igloo an Edmonton family had built a few weeks earlier, which also went viral: see A Rainbow Ice Igloo in an Edmonton Backyard.

Building the walls with slush mortar

Once the blocks were ready, the walls went up over a few frigid nights. For mortar he mixed slush with snow; in that cold it froze almost on contact, locking each translucent block to the next. Course by course, the scattered cubes turned into a square enclosure with thick, glowing walls.

If you try a smaller version at home, the same rules apply: freeze in sturdy containers that release easily, stagger the joints like brickwork, and wait for a properly cold spell so the slush sets fast.

The finished fort and the party

With the work done, Marchand invited friends and neighbours for a party inside the fort. Lit from within after dark, the coloured blocks glowed like stained glass. He was surprised by the reaction. “I didn’t intend for it to become as big of a deal as it was,” he told CBC News, after his photos drew press coverage from around the world.

For more homemade winter structures, see a different homemade snow structure, or stay in professionally operated seasonal igloo accommodation run by Iglu-Dorf in the Alps.