Garage doors don't typically require a lot of maintenance or adjustment, but there are occasions when they need attention. One such instance is when garage doors are no longer level; and closed, uneven garage doors leave a gap at the bottom between one side of the door and ground. This gap can lower the energy efficiency of your home, and it can also cause wear-and-tear on the garage door rails, rollers and opener. However, savvy homeowners can fix this problem fairly quickly with a few hand tools. Below is what you will need, as well as instructions on how to correct the gap.

Tools and materials needed

• 2 Garage door winding bars
• Adjustable wrench
• Eye protection
• Stepladder

Step-by-step instructions

1. Keep your safety in the forefront - garage doors are balanced through the use of powerful torsion springs; these springs are able to cause significant injury by hurling tools and chunks of metal at whomever is performing work on them. Below are a few safe working principles that you must adopt when working with a garage door:

• Use the proper-sized winding bars as provided by the manufacturer of the door - never trust your personal well-being to homemade metal rods or generic bars that do not adequately fit the winding cones. Be sure to match the shape of the winding bar head with the shape of the winding cone socket.

• Keep your head and limbs clear - if a winding cone or torsion spring breaks, then the uncontrolled release of energy can cause a door to suddenly fall upon you or whip tools around. Never place your head directly in front of the winding cone, but stand off to the side when working.

• Wear eye protection - if a torsion spring pops or winding cone breaks, there is a good chance that some metal will be released from the accident. You must wear eye protection to keep you safe from possible missiles that could blind you.

2. Release the door emergency latch - pull the cord that unlatches your garage door from the electric opener trolley; this action permits the door to operate manually. Lower the door completely to the ground, and be sure that others in your home know not to attempt opening the door while you are working.

3. Loosen the winding cones at each end of the torsion springs - position the stepladder so you can safely access the winding cone on the side of the garage door that is closest to the ground. Insert the winding bar into the socket on the winding cone, ensuring that it is firmly seated, and grasp it firmly with one hand. With your other hand, use an adjustable wrench to loosen the set screw that holds the winding cone to the shaft. While maintaining a firm grip on the winding bar, allow the winding cone to slowly unwind. The winding bar will turn with the cone until it is blocked from further movement by the door; at that point, allow the tension of the spring to hold the winding bar in place. Move your stepladder to the opposite winding cone and repeat the process by inserting the second winding bar, holding it in place, loosening the set screw and allowing the tension of the spring to hold the winding bar against the door.

4. Loosen the cable drums - next, move the stepladder to the cable drum located on the same side as the first winding cone you loosened. With the wrench, loosen the set screw that holds the cable drum to the shaft, and allow the drum to naturally settle into position; repeat this process with the cable drum at the opposite end of the garage door.

5. Reattach the winding cones to the torsion spring shaft - once the winding cones and cable drums are loosened, the garage door should naturally settle into a level position. After verifying that there is no longer a gap beneath one side of the door, re-tighten the set screws holding the winding cones in position. After tightening the cones' set screws, slowly lift and remove the winding bars from their sockets. Be sure to stand clear in case the winding cones aren't firmly bound to the shaft and begin to violently spin.

6. Retighten the cable drum set screws - once the winding cones are tightly reattached to the shaft, tighten the cable drum set screws so they are again attached to the shaft. If either of the drum cables are loose, slowly rotate the drum to pull up the slack before tightening.

7. Verify proper operation of the door - following adjustment and reattachment of the cones and drums, re-fasten the door to the lift arm. Test the door for proper operation and check that the gap has been eliminated.

If this process doesn't fix the problem, it may be time to contact a local garage repair company.