Where should hook seams be caulked unless the slope is 1/25?

Hook seams are crucial components in HVAC duct systems, particularly when it comes to ensuring the integrity and performance of the system in managing airflow. When a slope is less than 1/25, the potential for water accumulation increases, which could lead to leaks or deterioration of the seam over time. Therefore, caulking the hook seams in these situations helps to create a watertight seal, preventing moisture from entering and causing damage.

On slopes greater than 1/25, the design inherently allows water to drain off rather than pool, reducing the risk of leaks. Therefore, caulking is not as critical in those scenarios. In cases involving low slopes, it's essential to apply caulk to maintain the longevity and efficiency of the ductwork by minimizing the chances for problem areas to develop. Thus, the recommendation to caulk hook seams specifically for slopes less than 1/25 is based on the need to mitigate these risks effectively.