How to Install a Door Jamb

A yellow front door.
  • 2-4 hours
  • Intermediate
  • $20-90
What You'll Need
Replacement door jamb (pre-made or custom)
Carpenters square
Wooden shims
Wood screws
Pry bar (optional)
Tape measure

If you have recently begun construction or repairs at home, you may find yourself needing to replace a door jamb. Door jambs can and will work their selves loose which can cause damage. This type of repair requires some basic carpentry knowledge, but is relatively straightforward.

Step 1 - Remove the Door

The first step is to remove the existing door. It needs to be removed for full access. Luckily it is a simple task. Simply remove the hinge pins and lift the door from its hinges. If you're not comfortable lifting the door by yourself, get a friend to help. Place the door safely out of the way before you move onto the next step.

Step 2 - Remove the Door Trim

Removing the trim is an easy task, but you must take care not to do any more damage. To proceed without damage, place the screwdriver or pry bar between the drywall and the trim. Then slowly and gently pry the trim away a little at a time. Once removed, set it aside with the door.

Step 3 - Remove Door Jamb

In most cases, a door jamb will be held down with nails so removing it will take simple prying. In newer homes it can be held down with wood screws. Either way, pay attention to how the door jamb is removed so you can preserve the hinged sides. Now remove it from its place.

Step 4 - Measure for the New Door Jamb

Next, measure the width and height of the door while staying within the side studs and door header/footer. With a pencil, mark the location of hinges on the opening by using the old door jamb as a reference. Make sure to measure from the center of each hinge location.

With these measurements, you can go to a local hardware store and pick up a pre-made door jamb or have a custom one cut for a little extra money. The custom fit door jamb will fit better, but you may have to wait a day or more before the hardware store has it completed. If you opt to get a pre-made door jamb, which is great for newer homes, it will come in three pieces and will need to be assembled before use.

Step 5 - Test, Level, and Plumb

Lay the new door jamb in place, only lightly secured at the hinged sides if you feel it is necessary. Place a level on top of your installation. If it is not level, use the shims to get the desired result. A carpenter’s square can be used to see if the install is plumb.

Step 6 - Make it Permanent

When you are satisfied with the level and plumb, continue screwing it into place and begin reattaching the trim and existing door.

Other Tips

Remember to wear safety glasses when cutting wood. Sanding the wooden pieces of the jamb before installation can save work when you are ready to paint or stain. Do not leave power tools plugged in without supervision.

If you follow this guide, you will be able to install a door jamb in no time.