DIY Garage Door Insulation for the Ends of the Door

Open the garage door about two-thirds of the way up so that you can access the bottom of the door without crouching or bending. Secure the door by attaching locking pliers on the chain just below the roller mechanism on one side.

Remove the nails from the existing weatherstripping using a flat-head screwdriver to pry out the strip, or a hammer and pry bar. Work gently so you don't mar or scratch the bottom of the garage door. Pull the old weatherstrip off and discard it.

Measure the bottom of the garage door, then measure and cut the new weatherstripping. Use a utility knife to make a clean cut.

Hammer the weatherstripping in place using roofing nails, unless the weatherstripping kit included nails. Check that the thickest edge, or the edge with the round foam-filled tube, is facing the outdoors. Start in the middle of the garage door, then alternate left and right sides, working your way out to the ends. Put nails in about every 4 inches. Trim the ends as needed.

Test the new weatherstripping by closing the garage door and checking to see that the seal is lying flat, does not bunch or pucker anywhere and there are no gaps between the weatherstripping and the ground.