Badly aligned rollers inside the bottom of a patio screen door will cause the door to bind or stick when opening or closing. This stresses the corners of the door, and if the corner joints become loose, the door will eventually fall apart. But you can adjust the door to glide smoothly with just a screwdriver. You’ll find two adjustment screws at the bottom of the door, one at each end, that raise or lower separate rollers. Adjust them as shown here.