What is the primary purpose of installing an underlayment for roofing?

The primary purpose of installing an underlayment for roofing is to prevent water intrusion. Underlayment serves as a secondary barrier beneath the primary roofing material, protecting the underlying structure from water that may penetrate through the roof covering. This is particularly crucial in areas where ice dams, wind-driven rain, or other weather-related issues may compromise the roof surface. By acting as a waterproofing layer, the underlayment helps to direct any moisture that gets past the roofing materials away from the roof deck, thereby minimizing the risk of leaks and water damage to the interior of the building.

While enhancing aesthetic appeal, providing additional insulation, and supporting weight might be considerations in some contexts, they do not represent the primary function of roofing underlayment. The fundamental role of an underlayment revolves around moisture management and safeguarding the building's integrity against the elements.