Overhead garage doors usually span from 8 feet to 16 feet across. When they're left open for long periods of time, day after day and year after year, gravity takes it's toll; your door begins to sag a little and after awhile the center is far lower than the outer edges. That's why most modern overhead doors have two long bracing rods supported by brackets at the top and bottom of the door. Each bracing rod runs through three brackets, one at each end of the long rod with a taller triangle-shaped bracket in the center. The bracing rods are threaded, and a nut and washer tighten up on the end brackets, drawing it taut and putting upward pressure on the taller center bracket. The latter, in turn, pushes up the center of the door and eliminates unsightly sagging. As time passes, a few more turns on either end draws the rod still tighter -- and sagging again is gone. If you have a very old type garage door without bracing rods, do-it-yourself brackets kits are widely available. And that's the On The House tip for today.