[header] How to seal a door [title] Tighten the hinges on your door. [step] Some drafts can be caused by loose hinges, so before you seal the edges of your door, you should take a few minutes to tighten any hardware. [substeps] Lift the door by the doorknob. 
If you can move it upward, the the hinges are probably loose. Use a screwdriver to tighten the screws holding the hinges in place.