Last pull a measurement from the top of the 2 x 6 piece of lumber that you just installed to the ceiling of the garage.
Garage door header construction.
These fabricated wood products can span longer distances and carry greater loads.
The width of the rough opening should be 3 inches greater than the width of the garage door you are purchasing.
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.
The beam they have specified now is 3 1 2 x 12 x 18 9.
This piece of lumber will be used to attach the center bracket of your garage door spring assembly.
If it s 9ft the opening must be 9ft 3 inches and so on.
This beam is suitable for garages with a second floor above.
Attach lumber to the face of the garage wall to the edge of the garage door header.
Building a structural header for a garage door opening can be handled on the jobsite and will offer the same structural support as more expensive solid wood beams.
That means you will place wall studs every 16 inches.
Layout the bottom plate and one of the top plates at 16 on center.
Big headers for big openings garage doors and other large openings require headers too beefy to be made from standard lumber.
For instance if the width of the garage door is 8ft the rough opening should be 8ft 3 inches wide.
Local and national building codes have specific structural requirements pertaining to beam sizes to span specific wall openings relative to the wall loads so consult your local building department before beginning this.
You get the picture.
The procedure for constructing a header for 6 inch exterior wall framing can be modified for any wall thickness.
Place your door openings where you want them and layout the correct rough opening size.
On previous projects i have been supplied a glu lam boise makes specifically for garage door headers that was 3 1 2 x 11 1 4 x 18 9.