How to reseal your garage door
Garage doors have a long strip of vinyl or rubber that attaches to the bottom of the garage door to keep out water, dirt, wind, and pests but over time the seal can break down. A great indicator that your seal needs to be replaced is if you see light coming through the bottom of your door.
To replace your seal, you will need to figure out exactly what type you will need. Some doors have an aluminium channel at the bottom that holds a u-shaped rubber gasket, the gasket simply slides into two tracks for installation.
Wooden garage doors tend to use a simple strip seal with angled edges which are installed with nails.
You may also want to consider purchasing an extra seal for the top of your door if you do not currently have one. They are strips made of rubber that you attach to the top of your garage door.