SC Heating Practice Questions - South Carolina Heating Contractor Examination Exam

A single screw at the top and no lap Not less than three sheet-metal screws or rivets spaced equally around the joint; crimp joints lapped not less than 1 inch with the male end extending in the direction of airflow Duct tape only, with the female end facing upstream Snap-lock joints need no mechanical fasteners even when used as the sole closure outside conditioned space