Shore up your garage door

How to seal garage doors the easy way

Learning how to seal garage doors only takes a few minutes but offers years of savings and protection. You don’t have to put up with a drafty garage!

How to seal your garage door: Before you start

Troubled by a leaking or drafty garage door? You’ll be glad to know that sealing your garage door is easy and economical. In fact, it can generally be done in an afternoon and the benefits are well worth it.

Installing new weatherstripping or replacing the old one will:

  • seal out drafts and lower your heating bill
  • prevent moisture, dust, pollen, and cold wind from entering
  • stop insects, rodents, or other pests from getting in

In most cases, sealing your garage door can best be accomplished by installing weatherstripping around the sides and top of the door. Weatherstripping is a flexible vinyl or rubber gasket that is attached to the jambs and seals the gaps when the door is closed. 

How to seal garage door sides and top: Step by step

Before you begin, make sure you have the right materials and tools at hand. Measure and purchase the weatherstripping and decide what type of fasteners to use. For best results, you will also want to add some adhesive or sealant as you install the weatherstripping to further reduce any air or moisture leakage.

Here is a quick and easy way to figure out how much weatherstripping you need:

  1. Measure from the floor to the top of one side of the garage door and multiply by two.
  2. Add the width of the door from jamb to jamb to find the total length of one garage door.
  3. If you have more than one garage door, multiply your total by the number of doors.

Here is a handy checklist of tools and supplies:

  • small pry bar (if removing old weatherstripping)
  • tape measure 
  • utility knife or snips to cut the weatherstripping
  • fasteners: hammer and nails (or pneumatic system), or screws and cordless drill
  • household cleaner and paper towels
  • sealant/adhesive
  • caulking gun

Now, to install your weatherstripping, follow these steps:

  1. If old weatherstripping needs to go, remove it with a pry bar or similar tool.
  2. Clean the door jamb with a cleaning solution and some paper towels. Make sure to remove old residue.
  3. Fill any holes or splits in the wood with wood putty. Sand and smooth where required.
  4. Measure and cut the top piece of weatherstripping with a utility knife or snips.
  5. Install the weatherstripping. Work with the garage door closed. If using adhesive, apply a thin bead first, then press the weatherstripping into place. It should be snug against the door but not too tight. Finally, secure it with nails or screws.
  6. Repeat this process for the sides of the door. Make sure to work from the top down and press the weatherstrip tight against the top corner.
  7. Check for gaps by lightly pushing the door and observe the seal on all sides. If any gaps occur, adjust the seal placement by moving it closer.
  8. If using sealant, run a bead along the inside edge of the weatherstripping as an additional barrier.

Some weatherstripping types are ‘peel and stick’, with adhesive strips already attached. Follow the manufacturer’s suggestions for easy installation.

Final touches and maintenance: How to seal garage door gaps

As mentioned above, you may want to add a bead of sealant along the inside edge of the weatherstripping after installation. Or you need to add some sealant from time to time if any of the weatherstripping starts to pull away from the door jamb. What type of sealant is best?

We recommend a high-quality acrylic latex sealant. Latex sealant is easy to work with, simple to clean up, and paintable. It’s a good idea to use exterior-grade sealant in a garage since exterior sealants are better at standing up to moisture and temperature changes. 

If moisture or water leakage is more of an issue, you may want to go with an exterior-grade silicone sealant. Silicone is your best bet for moisture protection and is very durable. Pure silicone, however, is not paintable, so choose a compatible colour or a clear sealant.

Need to make a minor repair? If a small section of weatherstripping is loose, glue it down with Loctite Extreme Gel. This high-strength adhesive bonds to nearly any surface yet remains flexible to withstand impact and vibration. Extreme Gel dries crystal clear and is highly resistant to water, UV light, and extreme temperatures.