Is ventilation really important?

Yes. Attic ventilation might seem like a minor consideration, but when done properly, it can extend the life of your attic and roof structure; and save you hundreds of dollars in repair and energy costs. In the summer, hot, moist air in the attic can warp roof sheathing and cause shingles to deteriorate prematurely. A hot attic also makes a home more difficult to cool and can result in added energy costs. In the winter, an overheated attic melts snow and can form ice dams at the roof edge. Water can back up under your shingles, wetting and damaging insulation and, eventually, the structure of the roof itself. Ice dams can even cause leaks inside your home, resulting in drywall damage.  more