How to Square an Uneven Door Frame

When installing a door assembly, it is important to know that the door frame is level and square. Cutting corners will only cause problems with your ability to open and close the door easily. So, if you're having issues with a door sticking in your home, and all other problems have been checked, it might be time to fix the frame. If you follow the rules supplied in this article, you can readjust a previous installation error or decrease the amount of error possible on a new door install.

Step 1 - Remove Door and Trim

If you're adjusting an existing door frame in your house, first, you will have to remove the door itself and all of the trim surrounding the frame. The door is simple enough; just pull the hinge pins out of place, tapping them from beneath with a screwdriver and mallet if necessary.

For the trim, wedge a flat pry bar underneath the edge on one end of a section, and gently pull the casing away from the wall. Do the same thing for all of the pieces around the door frame and carefully set them aside to reuse later.

Step 2 - Square the Opening Off

It is difficult to ensure that a door will be level and square if the rough opening is not (the rough opening is the bare bones structure before any work is done to begin a door install). So, before you begin, use a carpenter’s square to check the upper corners. This will save you time and effort later on. Remember, the more accurate your measurements, the more level your door will be.

Step 3 - Level Working Surface

Working with an uneven surface will also negatively affect the rest of the project, so check to see if the floor is level. If it isn't, make a mental note of the difference for future use. Writing it down is also a great idea.

Step 4 - Shim Door Frame

Placing a pre-hung door in the rough opening will give you an idea of how it will ultimately fit. This type comes complete with a pre-made frame surrounding it, so all you need to do is carefully slide it into place and shim wherever you need around the frame to level it in the opening. Remember that wooden shims can simply be made of wedges or blocks of wood.

Place a level against the door frame in your existing installation to see where you need adjustments. Then, like before, place wooden shims until it sits as it's supposed to. To keep the shims in place, nail them to the hinge. Make sure you trim any excess pieces with a saw so they sit flush with the wall.

Step 5 - Get a Level Sill

Next, adjust the door sill with a flat bar or wedge until it too is level. Place the wedge or bar under the latching side of the door frame and have a helper hold your door so you can check to make sure whether the top of the frame, or lintel, will need more adjustment.

Step 6 - Double Check

It is important in every project to double check your work. Take the time to measure the gap between the door frame and the original rough opening. Use and nail in more wedges where necessary. If you have the extra set of hands to spare, have someone re-measure if you feel it could be adjusted differently.

Step 7 - Secure Door Frame in Opening

Place your blocks of wood and/or shims into the open space over the lintel, and begin attaching the door frame to the original rough opening. Again, double check each corner to be square, before completely securing it into place.

Extra Tips

Do not worry about the finishing touches just yet. You can add framing to the door after applying the paneling or drywall. Also, head and side casings will finish off a new installation nicely, covering all your small shim adjustments.

Square An Uneven Door Frame FAQ

How do I make sure my door frame is square?

You can use a standard handheld level or a laser level to check if your door is square, but it can be a bit difficult and there are better tools for the job. Door levels are specifically designed for doors and they are easy to use.

A door level will tell you if the door is both level and plumb, which is what you need a door to be.

Why is my door uneven?

Doors that were once perfectly hung can become uneven over time. Door screws can become loose and cause the door to hang unevenly, but this problem can be fixed by tightening the screws.

You can also drive screws into the door jamb to try to shift the frame of the door in the direction you need it to go.

Should I sand the door or the door frame?

You can sand the door or the frame to get an evenly-hanging door, but it is easier to sand the door. The frame is more difficult, so it's better to stick with an easier task.

How much does it cost to adjust a door frame?

Repairing a door frame with an uneven door is a fairly inexpensive project, whether you choose the DIY route or hire a professional handyperson. You will pay around $75 to $250, depending on how extensive the repair job ends up being and how much you need to do to fix the problem.

Is it hard to fix a door frame?

Even for a novice DIYer, repairing or even replacing a door frame is not a difficult task. You can get this done with some basic tools, including a chisel and a screwdriver, and affordable materials, like wood filler.

The entire job should take only a few hours. Some things could complicate this job, however, such as severe damage due to termites, water, or a similar destructive force.