Both headers and girders are beams that are oriented horizontally and transfer load down to walls piers or posts.
Garage door header span.
Their is no notching permitted in the center third of any beam.
Portal frame details within the irc specify simple span headers with a maximum finished opening width of 18.
Window door garage door headers supporting roof wall floor loads.
Most door frames that are 4 feet wide or less require a 2 by 6 header.
Window door garage door headers supporting roof loads only.
Measure the width of your door frame.
When in doubt use 2 by 12 inch headers.
Notches on the outer thirds must not exceed 1 6 of the width of the board.
Between 4 and 5 feet the header should be built 2 inches wide and 8 inches long while a larger opening needs a header that is 2 by 12.