Some is Good, More is Better? or, Why Three Hinges on a Gate Isn't a Good Idea

In the past month I've talked to several fence contractors who shared the same misconception. In each case they thought that adding a third hinge to a gate would allow a heavier gate to be hung safely. There are several reasons why this is not so.

The first is that, no matter how hard you try, you will never be able to get all three hinges aligned in a straight line. There will always be a straight line between any two of the hinges, but to get all three in perfect alignment would be a tough job with a laser in perfect lab conditions, much less in the field. Why does that matter? Because the “odd man out” hinge will tend to push or pull on the gate frame, twisting it and leading to damage to both the gate and the hinge affected. To make matters worse, the hinge that is odd man out can change, depending on how far open or closed the gate is in its arc of travel.

Several of the contractors I talked to pointed out that the doors on their house have three hinges. That's often the case, and as someone who worked as a carpenter for nearly twenty years, I can say that the chief reason for that is wood doors are not stable without a third hinge. The center hinge on a door is there to make the door more rigid, not to support the weight of the door. See the following article for deeper understanding of this. http://bit.ly/1hgisiZ

A second reason is that the weight of a gate is primarily borne by one hinge, not two, or even three. Unless you spend a lot of time perfectly balancing the hang weight of the gate from the hinges, one hinge will likely carry the bulk of the weight, most of the time. Think of an old wrought iron gate installation. The ring and pin hinges used for hundreds of years work well as an example. The bottom pin carries the weight, the top pin serves as a pivot to guide the gate through its arc and keeps it from tipping over.

“So how do I hang this heavy gate”, you ask? That's the subject of the next installment.