ASTM C542-05 (R2017) PDF Download

The ASTM C542-05 (R2017) standard sets forth the required properties for lock-strip gaskets. These gaskets must have resistance to sunlight, weathering, flame, oxidation, permanent deformation under load, and retention of gripping pressure. The gaskets are made from an ozone-resistant compound and should not rely on surface protection that can be removed by abrasion, detergents, or other means to maintain ozone resistance.

Several tests are specified in the standard to evaluate the gaskets' performance. These include the tensile strength test, elongation test, tear resistance test, hardness test, compression test, brittleness temperature test, ozone resistance test, heat aging effect test, flame propagation test, and lip pressure test. The gaskets must meet the requirements specified for each of these tests.

The standard also includes some important notes and precautions. Note 1 states that the requirement for flame propagation can be waived by the architect or professional engineer if it does not conflict with local codes or ordinances. Note 2 emphasizes that the gasket is only one component of the overall system, and the structural integrity and weather-tightness of the wall depend on proper design and installation of the entire system.

The standard references the use of Test Method C1166 to measure and describe the properties of materials, products, or assemblies in response to heat and flame. However, it clarifies that this test method should not be used to evaluate the fire hazard or risk under actual fire conditions. It also provides a precautionary caveat highlighting the responsibility of the user to establish appropriate safety practices and consider regulatory limitations.

The standard concludes by stating that there are no known comparable standards published by other organizations that cover the same requirements.