What is the primary purpose of roofing underlayment?

The primary purpose of roofing underlayment is to provide an additional layer of water resistance. This crucial component acts as a secondary barrier against moisture infiltration, which can lead to leaks and damage within the roofing structure. Underlayment is typically installed directly onto the roof deck before the shingles or other roofing materials are applied. It helps protect the interior of the home from water that could seep through cracks or gaps, particularly during heavy rain or snow.

By serving as this added layer of protection, underlayment plays a vital role in maintaining the integrity of the roof and ensuring the longevity of the roofing system. The right type of underlayment can also improve the overall durability of the roof by resisting common challenges, such as wind-driven rain and ice dams, thereby safeguarding the underlying materials and the structure itself.