Screw the 2 x 4 s back together reforming the 36 inch by 12 inch l.
Framing arched garage door opening.
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.
You get the picture.
Nail or screw 2 x 6 jambs to the framing on the top first and then the sides of the rough opening.
This will give you room to space the door frame off of the sub floor.
Framing rough opening sizes are really quite simple.
This is usually done by fastening two 2 6 s to the back of the frame from the floor to as high as the hardware will go to.
Measure spring line from the floor to point at which the arch begins to curve.
This lumber will be used to attach your garage door track and a portion of your assembly.
For standard hardware this is usually around 18 inches above the header.
Measure layout and cut two plywood arches that represent the top of your arched door opening 2.
Measure door height from the floor to the center of the arch.
Measure door width from door jamb to door jamb.
For instance if the width of the garage door is 8ft the rough opening should be 8ft 3 inches wide.
If you are using a raised panel door the edges of the panels will disappear behind the wall if you make the opening too small.
Screw the plywood to both sides of the l placing a three inch screw every six inches.
Pull a measurement from the floor of your space to the ceiling next to the door opening.
The width of the rough opening should be 3 inches greater than the width of the garage door you are purchasing.
Speaking of disappearing panels and arched openings this also brings up the question of what is the best type of garage door to use.
Cut the header from 2 x 12 lumber and to a length of the rough opening plus 6 inches.
Rip several pieces of wood blocking to the width of your framing lumber minus the thickness of the two pieces of plywood in this case a 2 4 minus two 3 8 in.
If it s 9ft the opening must be 9ft 3 inches and so on.
To me this destroys the whole look of the house and only shows a lack of planning.
Pieces of plywood equals 2 3 4 inch wide blocking 3.
Just add 2 to the width of the actual door size.
Back framing the garage door first the inside vertical jambs are lined with wood to mount the track to.
Cut two 2 x 6 pieces of lumber and attach to the face of the wall running from the edge of your garage door jambs to the ceiling of your garage.
Place a corner in the corner of the garage door opening and screw through the 2 x 4 s into the framing of the garage door opening.
Verify width at bottom middle and top of door opening.
Repeat the process to form the other corner.