Massive snow accumulation on a roof creates the potential for an unpredictable avalanche-like effect. Metal is a great choice for your rooftop. It has a long life expectancy and can stand up to the harshest conditions. It does have a low coefficient of friction though–meaning things (including snow) don’t stick to it very well. But the notion that snow is intended to slide off a metal roof is misguided and can be dangerous.
