The door that goes out to my garage is in need of some auto-close action. I'm thinking of putting one of these in...

Everbilt 3-1/2 in. x 5/8 in. Radius Satin Chrome Adjustable Spring Door Hinge-20114 - The Home Depot

Here's my question...these hinges are sold individually. Is one all I need and if so, which one on the door should I replace?

 

First confirm that you want the door to close. I've run into two types of spring hinges. One allows you to adjust both the direction (opening or closing) and the force. The other, like your link, only closes.

I usually install one hinge in the center of the door. This allows you to leave the top and bottom hinge in place to hold the door while you work. Sometimes the size of the spring hinge is different so you might need to do some chiseling to enlarge the mortise.

 

I have this on my door: Universal Hardware Light-Duty Aluminum Residential Hold-Open Door Closer-4011 - The Home Depot You can adjust the speed and it has a stay open feature. Check the weight of your door since they make a heavy duty one also.

 

They go by the weight of the door, if you can find the manufacturers specs they will include that info. But in general, for a lightweight hollow door one will be enough. For a solid core exterior door you will need at least two, maybe three if it is 36" wide or wider, or if it requires more than a light shove to latch.

The strength of the closing force is adjustable to a degree, but the higher the setting the faster the spring wears out, so you are usually better off using 2 or 3 and setting them to lower force each than cranking them way up.

Spring hinges are convenient and don't have the "industrial" look of a closer, but the closer is a better solution for really heavy doors, or doors that that take a lot of force to close and latch.

Neither the spring hinges nor the closers work very well if you just open the door far enough to slip in; the door needs to be opened to close to 90 degrees to store the energy needed to close heavy doors.

When retrofitting spring hinges make sure you get the right size and style. They vary in the screw layout and the rounding radius of the corners. It's much easier to get an exact match to your existing hinges, although if your existing screw holes are loose or stripped out, changing screw layout pattern can be an easy fix. You will find online source have a wider variety than the borg.

 

Or you could use a gravity hinge. The surface of where the barrels meet is angled so the weight of the door pulls it closed.

 

Awesome info here. Thanks so much. There was surprisingly little info on these hinges out on the interwebs, so I really appreciate the help!