Adding a rubber seal to your garage door bottom prevents drafts, insects and small animals from entering your garage and protects the bottom of the door. Rubber and vinyl strips specifically designed to fit on garage door bottoms can be found at most hardware stores. You'll also need tacks and a few other simple items that you probably already have to seal your garage door bottom.
Measure the length of the bottom of your garage door with a tape measure so that you can cut the strip of rubber or vinyl to the appropriate size.
Cut the strip to the exact size of the length of your garage door bottom with a pair of scissors. Use a ruler to cut a perfectly straight line.
Lift up your garage door until the bottom is just over your head. This angle will allow you to tack the rubber or vinyl seal to the door.
Tack one end of the rubber or vinyl seal to the bottom of one end of your garage door using two tacks and a hammer. Attach one tack closer to the front of the door and one closer to the back. You may need a partner to hold up the other end of the rubber seal while you're doing this so that your tacks are not ripped out.
Repeat Step 4 at the other end of your garage door.
Hammer in tacks along the bottom of the rubber or vinyl seal all the way across the bottom of your garage door, with two rows of tacks spaced about 3 inches apart. One tack in each row should be near the front of the bottom of the door, and one near the back.
Close the garage door. Your new seal should eliminate gaps between the bottom of the door and the concrete and prevent noticeable drafts.
If you have an especially heavy piece of rubber stripping, don't be afraid to add more tacks to keep it up.