Petrick said water from a garden hose, which is usually in the mid-40s, can dissolve rooftop snow, as can nylon stockings filled with calcium chloride and tossed upon the roof. Like the other experts, though, he had a warning for overambitious do-it-yourselfers.
Heavy snowfall takes a toll on Chicago-area roofs — and collapses could be just the start of the misery
