However the correct answer should be that you want the finished opening to be the same size or slightly smaller than the door so the rough opening will depend on what you are putting on the sides of the opening and underneath the header.
Rough opening size for 9x8 garage door.
Always consider the car dimensions while designing a door opening and choosing right size of the garage door.
On each side although some systems can require up to 5 1 2 in.
Standard sizes standard garage doors in our area are 8 9 16 and 18 wide.
If you are installing a 9 wide door the opening will be 9 3 wide.
Also make the rough opening 1 5 taller than the garage door.
Nail or screw 2 x 6 jambs to the framing on the top first and then the sides of the rough opening.
Cut the header from 2 x 12 lumber and to a length of the rough opening plus 6 inches.
Getting the rough opening size right the first time will save you from frustration when installing your doors.
Leave at least 5 of space on the sides of the door.
If the door is 7 tall frame the opening 7 1 5.
Just add 2 to the width of the actual door size.
Install the header on top of the trimmers and nail.
99 of the residential garage doors that we run across are different than these widths.
Framing rough opening sizes are really quite simple.
You should add 2 1 2 to the height of the actual door.
Frame the rough opening to 3 inches wider than the garage door size you have selected.
1 2 or 1 in one direction of the other will won t typically.
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.
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.
Install the header jambs and center pad of the frame using a 2 x 6 lumber for the header jambs and center pad.
Most vertical track systems with torsion springs or other hardware require 3 3 4 in.
Leave a headroom of 14 or 12 minimum.
This post is intended for purposes of clarifying how garage door sizes work and opening preparation.
Make the rough opening 3 wider than the garage door.
The size of the door will be approximately the same as this sometimes called the rough opening next measure the sideroom or space available on the left and right sides of the opening.
Frame the rough opening to a height that is 1 5 taller than the door that you have selected.
This will give you room to space the door frame off of the sub floor.
