Garage doors come new with a weather seal attached to the bottom panel. This seal helps prevent water and other debris from blowing under the garage door and into the garage.
This weather seal can become dry rotted and pieces can tear off over time, leaving a gap under the garage door.
This weather seal can be replaced to help prevent water and debris from blowing into the garage. There are several types of weather seal, the two most common are bulb seal and t-seal. The actual weather seal threads into the seal retainer that is attached to the bottom of the door. The weather seal retainer can also be replaced if it is damaged.
If sealing around your garage door is important to you, then a vinyl trim is also available that seals around the top and sides of your garage door. This vinyl trim actually attaches to the garage door frame on the top and sides. The trim has a vinyl flap that seals against the garage door and helps reduce the amount of wind, dirt and water that can blow in at the top and sides of the garage door. If you are concerned about insulating your garage and helping to reduce energy use, then having a proper weather seal on the bottom, top and sides if the garage door is an important addition.
There is also a newer product on the market to help with sealing the bottom of the garage door and when used with the regular weather seal can add an additional layer of protection from water and debris blowing into your garage. This product is a vinyl garage door threshold that actually glues to the concrete and when the door closes on it the bottom weather seal and the vinyl threshold created a tighter better seal at the bottom of the door.