<p>An extension spring overhead door system in which the spring may be quickly and easily placed in tension with the door in a closed position. A spring tensioning device is provided which eliminates the need for multiple installers to lift the full weight of the door and then clamp or otherwise prop the door in an open position. An extension spring containment tube is also provided which surrounds the entire periphery of the spring to fully contain the entire length of the extension spring.</p>
