What is the primary function of mastic?

Mastic primarily functions as a flexible sealant, which is essential for sealing joints, gaps, and seams in various construction applications. This adaptability allows mastic to accommodate movement in building materials due to temperature changes, vibrations, and settling, preventing the ingress of water and air. Its flexibility ensures that it maintains a secure seal over time, making it a favorable choice for applications requiring durability and resilience against the elements.

While mastic may have secondary benefits that contribute to insulation and sound absorption in specific contexts, its primary role remains focused on sealing. Thus, its formulation is designed to optimize seal integrity rather than primarily function as a protective coating or insulator.