ASTM C1330-18 PDF Download

The ASTM C1330-18 standard specifies the requirements for cylindrical sealant backing for use with cold liquid-applied sealants in building seals. The standard defines three types of cylindrical sealant backings, namely type C, type O, and type B, each composed primarily of closed cell material, open cell material, and bi-cellular material, respectively. Various test methods are outlined in the standard for evaluating the properties of cylindrical sealant backing, including water absorption, density, outgassing, compression deflection and recovery, and tensile strength. It is important that the sealant backing is clean and free from any contaminants such as scale, foreign matter, oil, or water.

The standard also emphasizes that while it provides specifications for the sealant backing, it does not address the compatibility of the backing with the sealants it will come into contact with. Sealant compatibility needs to be confirmed by the sealant manufacturer. The ASTM C1087 test method can be utilized to determine the compatibility characteristics of sealants in contact with cylindrical sealant backings.

The purpose of using cylindrical sealant backing is to serve multiple functions, including limiting the amount and depth of sealant applied into a joint, acting as a bond breaker to allow joint movement without stressing the sealant, providing a form to assist the sealant in achieving the ideal shape factor, and acting as a barrier to prevent sealant flow through the joint. The standard states that no other comparable standards have been published by either ASTM or other organizations for this specific topic.