Having adequate overhang is very critical to the life and performance of exterior wood doors, and is generally required in warranties by all wood door manufacturers. In addition to complying with warranty conditions, a proper overhang will help protect your door from the elements and extend the life of the door.
So what is an appropriate overhang for wood doors? Generally, the amount of overhang required is directly related to the height of the door and is a simple calculation. In all climate conditions, the formula for determining the appropriate amount of overhang is: X=1/2Y (where X is the length of the overhang required and Y is the distance from the bottom of the door to the base of the overhang.) For example, if the measurement from the bottom of the door to the base of the overhang is 8 feet, then the “required” overhang is 4 feet.
Having an overhang less than the required amount will usually limit your ability to make warranty claims if there is damage to the door due to harsh climate conditions. Even worse, not having an appropriate overhang can expose your door to unnecessary wear and tear, making it age faster than expected and reducing the value of your investment. Since your exterior doors provide one of the first impressions of your home, ensuring it is protected with an appropriate overhang will help it stand the test of time.