I'm looking into thermally insulating the bottom of my Garage door (I live on Long Island NY, so the winters can get a bit cold), and I noticed that there are gaps in the sides of the garage door bottom.

What are these intentional gaps in the bottom of the rubber on the garage door?

Are they there intentionally?

Do they pose a problem for keeping the garage warm during the winter since air can go through them?

How would I get rid of them?

You can see it in the pictures that I shot:

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2 Answers 2


Looks like you need a new garage door seal that's the actual length of your garage door width, not several inches shorter.

I know my "nominal" 10 foot wide door is "actually" 10 feet 2 inches wide, for instance. But if I forgot that and got a "10 foot" seal it might come up short like that.


Rubber (and synthetic rubber) is stretchy and it's hard to install without stretching it.

If you stretch it when you install it it will shrink and after a year or so you get a result like that.

  • Having recently installed a new garage door seal, it definitely stretched as I pulled it into the groove, but it immediately snapped back to it's original size, there was no slow return. I find it hard to believe that the seal would have been stretched to fit on original install and have shrunk back over a year or so.
    – FreeMan
    Nov 17, 2020 at 19:14

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