Things You'll Need
Drill with socket adapters
Most garage door manufacturers recommend installing a strut on wooden garage doors that are more than 12 feet wide. They also recommend installing a strut on any door that is operated by a garage door opener. Sometimes, though, doors under 12 feet wide develop a bow in the top section. Doors without openers have no brace preventing warping and swelling at the top of the section. Door openers that attach to doors pull on the upper middle of the top section, causing the center of the section to bow over time. Garage door struts are available at home-improvement centers to fix your bowed garage door.
Measure the width of your door with a tape measure. Purchase a strut that is 1 inch shorter than the door width. Purchase four strut clips if you have a wood door, or two strut clips per stile for steel doors. Stiles are the metal braces that run from the top to the bottom of a door section.
Unplug the garage door opener power cord if your door uses an opener. Pull down on the emergency disconnect rope at the door arm to disconnect the door from the opener.
Remove the screws or nuts securing the bottom of the top roller bracket on the top section of the garage door with a socket wrench or drill with socket adapter. Do not remove the top securing screws or nuts.
Place the hole on one end of the strut over the threaded end of the bolt securing the bracket while your helper holds the opposite end, if your have a wooden door. If you have a steel door, align the hole with the mounting hole for the bracket. This puts the top flange of the strut over the bottom edge of the top roller bracket.
Secure the end of the strut to the bracket with the retaining screw or nut. Go over to the opposite end and repeat the process.
Place a strut clip on the lower strut flange on each end. Secure the strut clip to the door with a wood screws and a drill with a socket bit. If you have a steel door, use self-drilling tap screws to secure the strut clip.
Go to the center of the strut and attach a strut clip on the upper and lower flanges of the strut. If the door is bowing outward, ask your helper to go to the outside and press inward on the door panel until you secure the center of the strut.
Repeat the process of attaching strut clips to the door and strut at each door stile. Reattach the door to the door opener, if you have a garage door opener.
Although top sections bow more often, use the same process for any section on the garage door. Always place the strut on the bottom of the upper hinges on each section you install them.