As round two of the polar vortex descends upon the country, warnings are being issued again about ice dams, dangerous buildups of ice that can accumulate on your roof. These buildups can endanger the safety of your roof, create wear and tear, and lead to other problems, so make sure you stay on top of them. Here's the basic scoop: you need to keep snow off your roof and limit heat circulation near the surface of the roof.
If you don't, the heat seeping through the roof will partially melt the snow, which will freeze into ice, which will start to have a bit of a snowball effect (forgive us) as it solidifies into a dam that limits drainage, tears at roofing tiles, and leaves a formidable mess behind. You can address snow accumulation with a snow rake (it's dangerous to climb around on the roof!), and consider calling your New York roofer to upgrade the roofing insulation, thereby limiting heat loss.