Poor ventilation causes roofing materials to wear out prematurely. Heat builds up under the roofs surface causing shingles to crack and curl up from the outside. Inside, heat builds up in the attic, which increase utility bills and bakes the roof from the inside. Without proper ventilation, moisture can also build up to create mold and mildew. Eave vents suck cool air into the attic while ridge-vent or off ridge-vents exhausts it through the roof plane creating a vacuum that constantly circulates air. These products offer an inexpensive way to extend the life of a roof and keep utility costs down