In which situation would a compressible sealant backer be preferred?

A compressible sealant backer is specifically designed to accommodate movement, which makes it particularly suitable for expansion joints that experience changes in dimensions due to thermal expansion, contraction, or other dynamic forces. The ability of the compressible material to compress and then rebounding back to its original form is critical in allowing the sealant to function effectively while maintaining its integrity over time. This feature helps to ensure that the sealant remains adhered to the substrate and continues to provide a watertight seal, even as the joint expands or contracts.

In fixed joints without movement, a more rigid backing may be more appropriate, as movement is not a factor. Low-traffic areas may not require the dynamic properties that a compressible sealant backer provides, and decorative applications do not inherently necessitate movement accommodation. Thus, the compressible sealant backer is optimal in scenarios involving expansion joints where movement is inevitable.