What is Mastic?

Mastic is a versatile sealing compound used to create a protective barrier. In insulation applications, “Mastic” typically refers to a high-viscosity coating applied by trowel, brush, or glove. This is distinguished from “Coatings,” which generally have lower viscosity and are applied via brush or spray. However, in general industry terms, both may be referred to as mastics or protective coatings.

Key Functions:

In many instances, mastics provide physical protection to the insulation material itself. Their relatively thick application, combined with inherent strength and flexibility, creates a robust shell that the insulation surface alone cannot achieve.

Arguably the most critical property of mastics and sealants in any insulation design is their ability to protect the system from water (both liquid and vapor ingress).