How to Insulate the Hollow Frame of a Garage Door

Mix a bucket of warm, soapy water. Scrub the door, especially along the edges of each row on the door and the trim between the doors, with a heavy-duty sponge or cloth. Allow the door to dry completely before proceeding.

Measure each row of the garage door. Record the measurements, using the door width as the panel length and the height of each panel as the panel height. Label each panel separately to ensure accuracy. Garage doors consist of rows of panels, typically three or four, attached together in horizontal joints.

Unroll a length of double bubble radiant barrier insulation on the garage floor. Measure and mark the length needed, adding 3 or 4 inches to allow for error. It's easy to trim this off later.

Measure and mark the insulation to fit the height of the first panel. Add a couple of inches for leeway. Depending on your garage's specifications and the manufacturer of the insulation, the insulation may match the garage door panel height, it may need cutting to height, or it may require that you run more than one row of insulation across the panel to cover the entire section. Proceed accordingly.

Tape along the outer edges of the garage door panel with double-sided radiant insulation tape in preparation for attaching insulation. Depending on the door material, you can also drive staples, nails or screws through the insulation to help secure it in place or spray an adhesive along the center of the panel to aid adhesion. The insulation seals around nails and screws, which must be short enough to not penetrate the door completely.

Hold the first section up to the garage door. Position it as desired and press it into place if you're using glue or tape. Drive solid attachments such as staples or screws as needed to prevent sagging; the smaller the attachment the more closely it must be placed.

Continue cutting and hanging insulation across the other door panels. Cut slits in the insulation as needed to allow for garage door accessories such as the handle.

Overlap any rows by a couple inches. Use reflective tape to seal these seams, if desired, or any tears. Line hardware openings with additional tape.

Trim the edges as necessary. Test your installation, opening and closing the garage door to ensure everything is proper. Adjust as needed to ensure smooth operation.