Frame the rough opening to 3 inches wider than the garage door size you have selected.
Garage door framing opening size 8 x 6 6.
The height is 80 which is considered 6 8 or 6 8 add 2 1 2 to the actual door height and frame it 82 1 2 high.
Now all you need to know is how to properly frame your door rough opening.
Cut the header from 2 x 12 lumber and to a length of the rough opening plus 6 inches.
Ideally 2 x6 is the most used header size.
Step 1 measure the old door if you are replacing an existing door with one of the same size or the new door of choice if you are building a new garage.
The width of the lumber should be between 6 and 8.
If you are installing a 9 wide door the opening will be 9 3 wide.
The height of the rough opening would be the height of the garage door plus the thickness of whatever you are putting underneath the header in addition to the thickness of.
So if you have a bedroom door that is 30 wide which is considered a 2 6 or 2 6 door just add 2 to the width and frame it 32 wide.
Use 2 inch lumber for the jambs as well and ensure they are appropriately nailed to the door opening with the help of a nail gun or hammer.
If garage door height extends above the opening the headroom measurement should be adjusted proportionately.
Classic collection series 8 ft.
Width of garage door opening standard widths are 8 9 10 12 14 16 17 and 18 height of the garage door opening standard residential heights are 7 7 6 8 header the header is ideally a minimum 12 wide micro laminated beam that spans the width of the garage door opening.
After installing the jambs your garage door opening should now be the same size as the garage door.
If you are installing a 9 wide door the opening will be 9 3 wide.
Measure area labeled backroom 6 distance is measured from the garage door opening toward the back wall of the garage.
For instance if you have a 16 door and are using river stones that are approximately 2 to 2 1 2 you will want the rough opening to be roughly pun intended 16 6.
Nail or screw 2 x 6 jambs to the framing on the top first and then the sides of the rough opening.
Additional back room may be required for automatic garage door.
The rough opening is equal to the size of the door but you need to figure back head and side room before choosing and installing the new garage door.
Framing nails are highly recommended.