Install the bottom J-channel so it extends past the side casing about the width of the J-channel face. Cut a 3/4-inch notch in the back of each end, install it and bend the tab.

PITTSBURGH, March 14, 2025 /PRNewswire/ -- "I wanted to create a specialized J-Channel product that would eliminate the over cutting and scrapes, typically associated with metal building ...

Install J-channel Around Doors and Windows. Cut j-channel, or c-channel, depending on product, for all sides of each door and window opening.