Thank you, sir; I used to see those doors with that cable stretched diagonally all the time, when I was a little lad. These however were wooden doors (usually screen doors), not aluminum ones.
I just always thought the cables were used to strengthen the door; I had no idea they could be used to twist the door into fitting the frame.
I haven't seen one of those in a long time, though.
Well......there are several types of aluminum storm doors........the cheap ones are fabricated out of extrusions, pieced together with pressed joints.....these will sag over time, and can be repaired with the device that is described above.......
Most quality storm doors nowadays are welded together, and won't typically sag over time. However, since these doors also come with a built-in frame that attaches to the exterior of the house, if the house settles, and distorts the door frame, all you have to do is take the door, and the frame off the house, and remount it in a square configuration......problem fixed......sorta.....
doc