Depending on your opening the lumber width will be 6 to 8 wide.
Garage door header detail.
In an attempt to construct portal frames some garages are built with one continuous garage header extending over two or three garage door openings as shown in figure a.
Header details 24 25 nailing on narrow face 25 allowable holes 26 bearing length requirements 26 tapered end cuts 27 multiple member connections 28 29 columns 30 31 product warranty 32 some sizes may not be available in your region.
Frame the rough opening to a height that is 1 5 taller than the door that you have selected.
Header requirement 2 at minimum the header should be 12 wide with doubled 2 4 at opening and ceiling running the width of the door with a 2 4 in the center of the opening for the center bracket to attach to.
Portal frame details within the irc specify simple span headers with a maximum finished opening width of 18.
Header the header is ideally a minimum 12 wide micro laminated beam that spans the width of the garage door opening.
For instance if the width of the garage door is 8ft the rough opening should be 8ft 3 inches wide.
Free how to buy a garage door guide nationwide dealer network.
To finish the opening cut the header and jambs from 2 lumber.
The width of the rough opening should be 3 inches greater than the width of the garage door you are purchasing.
If the door is 7 tall frame the opening 7 1 5.
For deeper depth parallam.
You get the picture.