Adjusting door hinges may not be the first fix you would think of when you are having a problem with a door. At first when you look at door hinge, you think that there is no way to adjust them. In a sense, that is true. However, you can change the position of the hinge by using it to adjust the door jamb slightly.
Is this not your problem? See the article 'Fixing and Troubleshooting Doors' for a complete listing of all of the door topics.
How Door Hinges Support the Door
How can you make a door hinge repair when the hinges are sagging and the door will not close? To understand the answer to this question, you need to understand how the hinges support the door.
When a door has three hinges you might think, that each hinge is doing a third of the work. That would be fair, but it is not true. Of the three, the top hinge does the majority of the work. The bottom hinge acts as a fulcrum and the door will tend to sag, pulling at the top hinge.
Problems With Hinges
Top Hinge Issues
A top hinge that only has short screws attached to the frame will start to pull away in time. The frame itself may pull with the hinge. When this happens the door will sag, the top edge of the door on the strike side will start to rub against the frame. This makes the door difficult to close and can leave gaps where daylight comes in.
Door Hinge Mortise Problems
The mortise is the area of wood that is milled or chiseled away to allow the hinge to inset into the door or jamb. Problems can occur when the mortise is too deep or to shallow. This is not common on doors that machined at the factory. It is more common on hinges that are mortised and installed by hand.
A mortise that is too deep can cause the door to have too large a gap against the frame on the strike side. It can also cause the door to bind against the jamb, making it difficult to close. This is a fairly easy problem to fix, you can pack out the hinge with thin cardboard to get the hinge set at the right depth. See the section on 'Packing Out a Hinge' below.
A shallow mortise, will cause the opposite problem. The door might not fit in the opening correctly and may bind against the frame on the strike side. If you have this problem, you can deepen the mortises with a chisel. See the section on 'Mortising a Hinge' below.
Incorrect Hinge Installation
Again, this only occurs with hinges that are altered or installed in the field. Everything about the location of a hinge is important. The size of the hinge needs to be matched to the door, see 'Door Hinge Sizes', both for weight and thickness of the door.
The spacing of the hinges on the door must match the spacing of the hinges on the jamb. There is an inset and a backset for a door hinge. Too much inset/backset and the door will be too tight against the stop and may not close. Too little inset/backset and the door will have gaps at the door stop.
To avoid these types of problems, you should use replacement hinges that are the same size as the old ones. It is not a good idea to try and re-work the mortises to use hinges that are a different size. See the article 'Installing Door Hinges' for more information.
When mortising a new door slab to an existing opening, use extreme caution when locating the hinges. Try to use the old door as a template to get the spacing and backset correct prior to cutting the mortise.
The key to adjusting door hinges is the top hinge. You need at least one long screw that goes into the wood jamb that holds up the frame. If you are working on an exterior door you want to see the article 'Adjusting Entry Doors' for instructions on how to do this. For interior doors, see the article 'Adjusting Interior Doors'. Both of these articles provide tips on getting the door to set properly in the opening.
Packing a Hinge
To pack out a hinge you can loosen the hinges, (one at a time) and put one or more thin layers of cardboard (this should be dense cardboard, like the kind used for cereal boxes or similar) underneath the hinge.
The effect that the shims will have on the door are somewhat exponential. You do not necessarily need an 1/8" shim to correct an 1/8" gap. It will likely be less than that, depending on where the gap is.
Cut some pieces of thin dense cardboard, slightly smaller than the mortise for the hinge. Try one shim at a time until you get the door aligned the way you want.
Mortising a Hinge
Whoa!! Why do you want to do this. There are a few legitimate reasons, but most of the time this is not needed.
Do not get hinges for replacement that are a different size than the ones that were on the door. If you can't find the right size, go online to find them. See the article 'Door Hinge Sizes' and 'Door Hinge Types' for information on how hinges are sized and how to obtain them. See the article 'Installing and Replacing Door Hinges' for the best practices on replacing hinges.
Getting the mortises right by hand is difficult, so going at your door or jamb with a hammer and chisel is not a great idea.
Replacing a Door Slab
A legitimate reason may be matching a new door slab to an existing opening. For this I recommend getting a door hinge template kit. You can use a regular router and a special bit to cut the mortises. The better kits will have all the templates and accessories you need for whatever hinge size you have.
You can get a kit for around forty dollars. They include the templates that attach to the door or frame, a special router bit, corner mortising chisels if needed and charts on how to locate the hinges.
The hinges are an important component for any swinging door. When they are out of adjustment, the door will not operate correctly. There are things you can do with the hinges that will get the door aligned properly.