Besides wasted heat melting snow on roofs can mean ice dams where snow melts in a warmer spot on the roof and then freezes when it hits the cold eaves.
Snow melt patterns on roof.
Because the snow is melting from a heat loss on your roof and not because of warming temperatures the melted snow can refreeze once it travels from your roof creating ice dams that appear as icicles on the eaves and gutters.
On frosty and snowy mornings melt patterns will become readily visible.
Gently toss the tied off pantyhose onto the edge of your roof to begin melting the snow.
Place this vertically on your roof near the edge so it will melt a section of snow and ice creating an area where the water can leak off.
If your attic has little or no insulation the snow will disappear quickly.
Purchase sidewalk salt also called calcium chloride from your local hardware or big box store.
The patterns relate to attic insulation.
When snow begins to gradually melt off a roof vehicle or other outside structure you might occasionally see some odd patterns develop.
Winter storm central.
As you look at the patterns the mosaic of patterns will show which homes are more air tight and well insulated than others.