A simple slip of the foot can cause you to accelerate instead of brake, resulting in a bump against the garage door. If you are lucky, the low speed collision will result in little more than a scuff, but sometimes a dent or crack is the outcome. Fortunately, it is possible to repair this damage without replacing the entire door if you have a paneled rolling style door.
The extent of the damage determines the best repair method. If only the panel is dented, which is often the case with metal garage doors, you may only need to pop out the dent. A crack or hole is more likely if you have a vinyl garage door. This will require a full replacement panel, but it is still better than replacing the entire door. You also need to check the inside of the door, where the various supports arch across the back of the panel. Unless you hit the door exceptionally hard, these should be fine. If they are warped or bent, though, you may need to bring in a professional to complete the repair.
Pop out the dent
If you are lucky enough to just have a dent, you have a few options for popping it out. Sometimes it will pop out easily with some firm pressure. With the door closed, you can work inside the garage by placing a flat board over the dent. The board should be slightly larger than the dent. Now bang firmly on the board with a rubber mallet to pop out the dent.
For vinyl doors that dented instead of cracking, you may also be able to pop the dent out. You can first try pushing it out with your hands. If this fails, try heating up the vinyl with a blow dryer then pour ice cold water over it. Sometimes the temperature changes cause the dent to pop out.
Replace the panel
Panel replacement is a bit more involved. You will need to disconnect the automatic garage door opener as you work. Then, find all the hinges and bolts that connect the panel to the frame. Take pictures so you can be sure to reattach everything properly. Remove the old panel and then fit the new panel in place. Once everything is bolted back in place, open the door manually. If everything is balanced correctly, it should slide open and closed smoothly. You should also be able to release the door when it is halfway open without it slamming shut. If you have any issues, contact a garage door professional to troubleshoot the problem before reattaching the automatic opener.
For more information, contact a professional in your area or visit a website like http://www.raynordoor.com.