How To Install A Prehung Door: Fastest Way To Install

Installing a door takes patience and time, and you can grow frustrated if the framing is out of order. With the consistent latch snap, jamb clearance, and hinge swings a door should have, it is evident that hanging a door is a true mark of carpentry skill. You might be wondering how to install a prehung door?

A prehung door is a ready-to-install door with its frame and hardware. You might believe prehung doors mean more ease and speed installation, but it’s not that simple. The door and frame need to install correctly. If not, the door will not hang work properly.

This article will elaborate on all aspects of prehung door installation. Keep up, and you will be able to install your prehung door in the end.


Tips For Installing A Prehung Door 

Even though installing a prehung door is more manageable than constructing a doorframe from the beginning, attaching it is more complicated than just inserting the door unit and screwing it into place. With these tips, your job will go smoother than you think:

  • Do not remove your door unit restraints till you are ready to install the new door.
  • It is best to work with a partner as prehung doors are bulky and heavy to lift. 
  • Be careful while lifting and hanging the prehung door during installation. Uninstalled prehung doors are very delicate. 
  • For the perfect structure, always ensure the rough opening is not damaged and sized correctly. 

How Do You Install A Prehung Door?

In general, Prehung doors hang on the jamb or doorframe. The main jamb is the first to fit, and the door is attached. The frame has a casing attached as finishing. Follow the following steps to install a prehung door:

1. Inspect/Prepare The Wall Door Opening

The wall door opening should be a built-in size for the prehung door installation:

  • Make sure no nails or screws are protruding from the side studs.
  • Ensure the side studs are flat and not twisted or bent.
  • Give at least 0.15-inch space to the width and height of the door, and this is for accommodation.
  • Smoothen the header and the floor to be level and flat.
  • The doorway opening should be a square to the wall, and you can check with a framing square to be sure.

2. Prepare The Jamb

  • Prepare the rough door opening or trimmer by ensuring it’s the same size as the door frame. Make sure the frame is in squares by using your framing square.
  • Attach the jamb to the door frame and concentrate on the hinge side of the door. If the hinge jamb centers right, the door installation is halfway. 
  • Attach shims between the jamb and the door opening and check with your level if it is centered. If it’s not, adjust the door frame with shims till centered. The shims hold your jamb upright and tight to the door frame.
  • Screw the shims to the timer and check the walls for plumb (center balance) and measure the gap
  • Adjust the gap to equal the other hinge location using overlapping shims, and screw the shims tight. 
  • Cut the protruding end of the shims to size with a utility knife.
  • Check with your framing square if the trimmer faces are square to the door opening, and do a final check for plumb. With the jamb in sync, your door will be perfect.

3. Fit The Door Into The Jamb Opening

  • Fit the door into the opening and push the hinge jamb onto the shims.
  • Screw the hinge side into the trimmer and adjust the jamb until it fits properly.
  • With the jamb fit well with the door, screw the two hinges to the frame. If the wall doesn’t fit with the jamb, shim the hinge locations to hold it.
  • Fill all gaps or clearance between the wall and the casing with wood edges.

4. Adjust The Reveals Between The Door

  • Check that the reveals or gaps between the top and head jamb are equal and adjust if not. 
  • Swing the door to see if it fits well and laps perfectly.
  • Set all gaps and ensure the reveals are consistent and equal.

5. Anchor The Jamb

  • Strengthen the main jamb on all sides by adding shims and screwing them. Make sure to add extra screws for stud support.
  • Replace the hinge screws with longer ones to prevent the door from sagging.

6. Finishing

  • Attach the split jamb into the main jamb’s groove and nail together on all sides except the head jamb. 
  • With your door, all set, fix the latch bolt onto the door with the screws. Close the door and check all is perfectly fit in.

Using these procedures, you can now install your prehung door yourself.

What Are The Ways To Install A Prehung Door?

These are two different ways to install a prehung door.

1. Shimming

This involves installing the prehung door by inserting shims between the frame and the wall while keeping the door at a balance using a level and props. This method can be time-exhausting and frustrating for a beginner.

2. Ez-Hang

This method removes the need for shims. Ez-hang uses a bracket system, the brackets screw to the door opening, and the door is hanged and screwed together. 

How Hard Is It To Install A Prehung Exterior Door?

Installing a prehung exterior door can be difficult. The exterior doors can be large and heavy to lift. You can use clamps and blocks as props while you work. To make installation easier, get someone to help as support, to hold and help you lift.

How Many Inches Gap Should Be Around A Prehung Door

They should be a ⅛ inch gap between the trimmer and door jamb on all sides. However, exterior doors should not have a bottom opening or clearance. The absence of slots in the exterior prehung door is to prevent air, insects, and intruders from entering.

How Do You Fix A Prehung Door That Is Not Plumb

If your prehung door is not plumbing, follow these steps to get it right. 

  • Close the door and determine the unbalanced side of the hinge jamb
  • Remove the default hinge jamb and readjust the door using shims.
  • Then you can screw back the hinges jamb and check if it plumbs perfectly.

Frequently Asked Questions

What Screws To Use For My Prehung Door

It is best to use long screws of about 2″ and above. The average size of screw for a prehung door is 2.25″ screws. The Grk t-10 Torx finish screw is a great one. Use a long screw that gets into the timmer.

Where Do You Shim A Prehung Door?

Shims are fixed between the timmer or door opening and the door frame or jambs. You use a shim to hold the jamb tight and upright while working. Without a shim, the door sags and pulls the edge off. 

What Does A Prehung Door Come With?

The prehung door comes with different components, and all parts are connected to form a full door. The prehung door includes Jambs/door frame, casing, door, and doorknob. The style and size of the prehung door determine the price rate.

Are Prehung Doors Easy To Install?

Prehung doors are relatively easy to install, and are best for rough door openings. It’s convenient, easy to fit, and can be installed without professional expertise. Prehung doors help you avoid building a door frame from the beginning.

Should I Nail Or Screw In A Prehung Door?

You should use a screw in a prehung door. Nails can get loose after a while or bent while you knock them into the jamb. But screws hold better, are neat, and are easily hidden. It is also easier to unscrew if you want to uninstall the prehung door. 

How Do You Screw In A Prehung Door?

When you are screwing in a prehung door, screw at the back of the hinges. The screws will be hidden by the hinges, giving your door a neat look.

Should I Paint The Prehung Door Before Installing?

Yes, it’s easier to paint your prehung door after installing. Both sides can be painted with the door on its hinges. You can also coat the door first before installing and apply finishing paint to cover scratches and dirt acquired in the installation process.

How Much Does It Cost To Have A Prehung Door?

The cost of prehung door installation can vary according to the size, material type, and individual labor charge. The average cost is between $300 to $2000.

What Instrument Do I Need To Install A Prehung Door?

To Install a Prehung door, you need tools like; a prehung door, nails, screws, screwdriver, tape measure, level-4 foot, hammer, chisel, utility knife, plump bob, and drill. 

Does The Prehung Door Include Jamb?

Yes, the prehung door includes a jamb. The jamb is the door frame that is attached to the wall opening. Unlike the slab door, which has no pre-existing doorframe, the prehung door comes with its pre-fitted jamb.


The goal is to install a prehung door that swings back and forth flawlessly. To do this, make sure the jambs are all perfectly aligned and upright. Ensure that the gaps are equal and the shims tightly screwed. You will have a properly installed prehung door with all these in place.

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