Replacing Garage Door Bottom Seal

If you have an older garage door chances are the bottom seal is worn out. Replacing garage door bottom seal is easy to do. Most garage door bottom seals are relatively inexpensive and easy to purchase online. Before making any purchases you will need to determine the length, width, color and type of seal needed.

Measure the Garage Door

Most residential garage doors are either 9ft or 16ft wide. Measure your garage door opening to verify how many feet of bottom astragal you will need. It would be smart to purchases an extra foot of material to allow for shrinkage and folding each end in. If you have more than one garage door it would be wise to replace all of the seal at the same time.  Volume discounts are available for purchases exceeding 20 ft.

Types of Bottom Seal

The most common types of bottom seal are T type bottom seal and J type bottom seal. Be sure to match up the type of bottom seal you currently have to what you intend on purchasing. Aluminum retainers on the bottom of most garage doors only accept specific types of bottom seal. If you don’t have any seal on the bottom of your door you will need to examine the retainer channels. Retainers may have double channel or single channel systems. Garage Door Bottom Seal

Bottom Seal Profiles

Do you have a low spot in the concrete where water and debris leaks under the garage door? Selecting a wider profile bottom seal may help seal low spots. The most common profile is 3.5 inch although profiles up to 6 inches are available. If you are matching doors you will need to pay attention to the color of the seal. Common colors are black and gray, although yellow is available for commercial applications.

Installing Bottom Seal

After purchasing your garage door bottom seal you will need to remove the existing seal. This is best done by using a razor blade to slice the old seal in half. It is much easier to pull the seal out of the channel. After completely removing the old seal you will need to clean the retainer. Spray the aluminum bottom retainer with a lubricant like WD-40. You can use compressed air or a pressure washer if you have either available. A screw driver may be needed if you find bent spots in the bottom retainer. Use the screw driver to bend out any existing creases. After preparing the retainer you can start sliding the new bottom seal into place. It may be necessary to have one person pull on one end while the other person feeds the seal into the channel. Leave 2-3 inches extra on each side to allow for shrinkage and fold the ends back into the gap in the channel.

  • Remove Old Seal
  • Clean Out Retainer
  • Repair Bent Channels
  • Install New Seal
  • Fold Ends Back In



Garage Door Guide Cal
Hello, I’m Cal – owner of Garage Door Guide LLC    

I write tutorials about garage door repair, installation and maintenance. With over a decade of experience in the overhead door industry I’ve learned a lot and I’d like to share my knowledge with you.

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