What should joints and seams in ducts be if not continuously welded?

The correct answer indicates that joints and seams in ducts should be sealed. Sealing joints and seams is essential for maintaining the efficiency of the duct system. It prevents air leakage, which can lead to energy loss, increased utility costs, and reduced system performance. Properly sealed joints and seams contribute to better indoor air quality by minimizing the chances of unconditioned air from entering or escaping through gaps.

Using sealants that are compliant with code requirements ensures long-lasting and effective sealing. Taping is often used in conjunction with sealing, but on its own may not provide the same level of durability or effectiveness, especially in systems where pressure variability is a concern. Fastening may hold the components together, but without proper sealing, it does not effectively address air leakage. Exposing seams is not acceptable as it could lead to significant air loss and inefficiencies. Thus, sealing is the most appropriate method to ensure optimal duct performance.