See-through roof

A few days ago it snowed. The roof you see in the photo quickly changed from a quite uniform gray (which you can see in this old photo) to a beautiful snowy white.

 

Then the snow stopped and it started melting off. During the process, though, I noticed that streaks of snow lingered on the roof... showing the location of the rafters.

 

This gives an idea of the heat leaking through the roof, and the slight additional insulation afforded by the rafters' extra thickness of wood.

Done