ASTM C 542:2005

1.1 This specification defines the required properties of lock-strip gaskets where resistance to sunlight, weathering, flame, oxidation, permanent deformation under load, and diminution of gripping pressure are prime essentials. Note 1 -The requirement of flame propagation may be waived by the architect or professional engineer when doing so does not conflict with local codes or ordinances. 1.2 This specification applies only to the "locking" compression type of gasket, sometimes referred to as the "zipper" type. Note 2 -Structural integrity and weather-tightness of the wall requires the sound design and installation of the entire system of which the gasket is only one component. 1.3 The values stated in SI units are to be regarded as the standard. 1.4 Test Method C 1166, as referenced in this specification, should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use. 1.5 The following precautionary caveat pertains only to the test method portion, Section 7, of this specification: This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.6 The committee with jurisdiction over this standard is not aware of any comparable standards published by other organizations.

91.100.50