Used as a double-layer starter course for CertainTeed's Presidential and Presidential TL shingles, Presidential Starter combines durability and flexibility for better resistance to blow-off. Two layers need to be applied. The Integrity Roof System is designed to provide optimum performance-no matter how bad the weather conditions are. Presidential Starter meets the accessory requirements for the CertainTeed Integrity Roof System, which is comprised of underlayments, shingles, accessory products and ventilation all working together.