[gen220]

You have to poke holes in the ceiling, and make sure the they’re clear every day.

If you light a candle, the snow will melt and freeze into a film of ice.

The holes are important for ventilation in general, but it also allows vapor to escape.

When we built them we’d use ski poles to make the holes. You don’t want them to be too big or you risk the structural integrity of course. There was a ratio of hole count : people that we followed but I can’t remember that detail (: