Close the garage door fully and walk to the outside of the door to seal up the gaps.
Measure the vertical height of the garage door at the location where it meets the wall. Lay a long strip of vinyl weather stripping on a table and mark it at the same height using a pencil. Cut the strips to size using scissors.
Place one of the strips up to the side of the wall where the garage door meets the wall. The flexible flap should cover the gap and lay flush on the garage door. The side of the weather stripping with the screw holes must face the wall.
Insert self-tapping galvanized screws into each screw hole, using a power drill to insert them fully.
Insert a tube of exterior-grade caulk into a caulk gun and apply a one-eighth-inch bead along the side of the weather stripping that meets the wall.
Repeat the process to apply weather stripping and caulk to seal the gap on the other side of the garage door.
Walk back inside the garage and examine the wall areas directly beside the door to see if there are any gaps outside of the frame. If gaps are present, fill them with expandable polyurethane foam until they are closed.