Roofing underlayment is a protective layer installed beneath roofing materials, such as shingles or tiles. It serves as a barrier against moisture, preventing water from seeping into the roof structure. This helps to protect the underlying wood and insulation from damage caused by leaks or condensation. There are different types of underlayment, including felt paper and synthetic options. Each type has its own benefits, such as durability and resistance to tearing. Proper installation of roofing underlayment is essential for enhancing the overall lifespan and effectiveness of the roof, ensuring it remains watertight and secure.