Roofing experts throughout the US agree that if you want to get the longest lifespan out of your roofing system as possible, it will need proper ventilation, but attic ventilation is a lot more complicated than you might think. If you’ve noticed that you have a lot of icicles along the edge of your roof in the winter, or that your attic is especially hot in the summer, both are signs that you might have a ventilation problem. If this isn’t addressed sooner than later, you won’t be doing your shingles (or your gutters) any favors.