Rooftop underlayment, specifically designed to initiate the shingle application process by creating a consistent, straight edge along the eaves and rakes, is known as starter material. This product ensures proper shingle alignment and sealant adhesion at the roof’s perimeter, which are areas particularly vulnerable to wind uplift and water penetration. For example, a strip of starter material installed before the first course of shingles provides a double layer of protection at the roof edge.
The implementation of designated eave and rake protection significantly enhances a roof’s overall performance and longevity. By providing a uniform surface for shingle attachment, it reduces the likelihood of blow-offs during high winds. Furthermore, the added layer of waterproofing membrane at the roof’s edges defends against ice dam formation and water infiltration caused by driving rain. While pinpointing the exact date of initial adoption is challenging due to evolving building practices and materials, the concept of reinforcing vulnerable roof edges has been present in roofing for several decades, becoming more formalized with the development of specifically manufactured starter products in the later half of the 20th century.