How To Install An Interior Door That Is Not Prehung [9 Steps]

Interior door upgrades can help to rejuvenate your home. And if you are looking to install a new door in your home that is not prehung, what's also known as a "slab door," you may have questions surrounding how to go about it. In this post, we are going to answer those questions for you so that you'll have everything you need to get your door installed in no time.

Below, we've outlined the quickest and most efficient steps to install your slab door:

  1. Install the hinges
  2. Position the door to the top of the frame
  3. Position the door to the side of the frame
  4. Mark hinge locations with a pencil
  5. Outline the hinge placement on the door
  6. Chisel the door to create room for the hinges
  7. Test the hinge cut out
  8. Install the door
  9. Test the movement of the door

In this guide, we'll take a closer look at these steps and the tools/equipment you'll need to do so. We'll also discuss how long it takes to install a slab door, how much it costs to install, and more. So be sure to keep reading.

A house interior with door and sofa, How To Install An Interior Door That Is Not Prehung [9 Steps]

Steps To Install An Interior Door That Is Not Prehung

Interior with door and armchair

A slab door is a stripped-down, basic door that doesn't have a frame. Installing them requires a bit more effort, but they can definitely be installed as a DIY project. Let's take a look at how to install them correctly.

Tools you'll need:

  • Interior door slab
  • Door installation kit
  • Electric drill
  • 6-inch wood shims
  • Carpentry pencil
  • Utility knife
  • Measuring tape
  • Hammer
  • Safety glasses
  • Workman's gloves
  • Chisel

Step 1: Install The Hinges

After you've gathered all of your equipment, the first thing that you'll need to do is to place the hinges into the door jamb mortises (the cutouts for the hinge plates in the door frame). Using your cordless drill, take your 3/4-inch screws, place them inside the holes for the hinges, and drill them into the jambs (which should already have pre-drilled holes). Each hinge plate will need 6 screws, and the door should have two hinges.

Check out these satin door hinges on Amazon.

Step 2: Position The Door To The Top Of The Frame

Next, lift the door vertically and place it inside the frame in a standing position. Then, using your hammer, tap the wood shims beneath the door (two or three of them), and to the top of the door until it is 1/8 inch away from the top door jamb.

Check out this hammer on Amazon.

Step 3: Position The Door To The Side Of The Frame

While the door is still in position, take two more wood shims and place them on the opposite side of the door's hinges. Hammer them in place (between the door and the side of the frame) so that the door is positioned to meet the hinges on the opposite side. This will help the door fit horizontally into the frame.

Be sure to hold the door steady, as it will need to fall within an eighth of an inch of the hinges to open and close properly. Use your measuring tape to make sure that it's within an eight of an inch.

Check out this measuring tape on Amazon.

Step 4: Mark Hinge Locations With A Pencil

Outline the location of both hinges on the door with a pencil.

Check out this carpentry pencil set on Amazon.

Step 5: Outline The Hinge Placement On The Door

Remove the door from the frame and place it on your workbench. Next, unscrew the hinges from the frame and place one of them on the door where it will be installed. Using your pencil, trace around the hinge to align it with the marks that you made earlier.

Step 6: Chisel The Door To Create Room For The Hinges

Take your utility knife and cut around the hinge marks at a depth of 1/8 of an inch. Next, use your chisel and hammer to chisel the area around the tracings and make room for the hinges. Be sure to create a flat and even surface when using the chisel, so that the hinges will lay flat against the door when you screw them in.

Check out this retractable utility knife on Amazon.

Step 7: Test The Hinge Cut Out

Take the hinges and place them in the newly cut out area of the door to ensure a proper fit. If they don't fit, you may need to retrace the area and chisel it a bit more. It should have a snug fit in the tracing space of the door. Be sure to only shave a small amount of the door at a time using the chisel, as shaving too much can be a cumbersome task to fix.

Check out this wood chisel set on Amazon.

Step 8: Install The Door

When the hinge plates fit securely answer the door, screw them in with the 3/4-inch screws. Next, stand the door upright and place it in the door frame. Flip the hinge plate to the left or right so that it aligns with the cutouts in the door.

Next, use your hammer to tap the plates into the cutouts on the door. Once they're in place, use your screwdriver to drill the hinge plates from the door frame into the door.

Step 9: Test The Movement Of The Door

After you've drilled both hinge plates into the door, close the door completely and reopen it to test the fit. If it gets stuck, you may need to readjust the hinges or chisel out more of the door frame for the hinge placement.

Can You Just Replace The Door And Not The Frame?

Yes, you can definitely replace a door without replacing the entire door frame, as long as the jamb and frame are in decent shape. The new door will also need to be the same size as the previous door so that it fits the frame correctly. It's best to first measure the new door (and the frame) to make sure that this is the case.

How Long Does It Take To Install A Slab Door?

Installing a slab door can take around 5 to 7 hours, on average. However, it may take a bit longer for a novice door installer. If you're not up for the time investment, you can get a professional to do the job for you.

How Much Does It Cost To Install A Slab Door?

Depending on where you live and specific installation factors, installing a new slab door can cost you anywhere from $150 to $500. The biggest cost factors include any construction or repair needed for the current door frame, whether or not you need the lock kit and kick plates to be installed, and if the door will be painted or not.

If the door includes glass panels, it may cost a bit more to install. Also worth noting: if you have more than one slab door to install, contractors may offer you a discount. They may also offer a discount if you've purchased the slab door directly from them.

Is A Slab Or Prehung Door Better?

Neither door is better than the other, however, prehung doors are more commonly used because they are typically easier to install. They can be installed in 1 to 2 hours a lot of the time. Slab doors can take anywhere from 5 to 7 hours to install, as they typically require more steps to ensure that they fit the door frame properly.

Prehung doors come with hinges pre-attached, holes for the doorknob, and the strike plate already pre-cut--and they don't require the hinges to be mortised. So, they are way more convenient to install than door slabs.

On the opposite end, they can come with unexpected issues such as a flimsy frame. Also, they may have the wrong measurements for the door frame and require re-ordering or planing to fit the frame properly. This is something many homeowners try to avoid due to the amount of labor involved.

Slab doors can be a better option if you are looking to save money on the purchase of the door as they're typically less expensive than prehung doors (by 30%-50%). They also provide way more flexibility when it comes to the design of the door, which can be beneficial if you're going for vintage decor.

The biggest disadvantage of slab doors is the amount of carpentry work (particularly to cut the mortises for the door hinges) involved in fitting them to the door frame. This can require hours of work and can be especially difficult if you are not familiar with this type of carpentry.

They also typically need to be planed to properly fit the door frame. The extra labor effort required for slab doors may not be worth the effort to some homeowners, so it's important to decide how much work would be needed for your particular door frame before deciding to use a door slab.

Wrapping Things Up

Installing a door that is not pre-hung may require more effort than pre-hung doors, but it can be a great option if your current door frame is warped and you're looking for a customized fit to the door frame. Interested in more home improvement projects? Be sure to check out our other posts before you go:

How To Fix Misaligned French Doors? 

What Is The Best Door For House Interior?

Leave a Reply

Your email address will not be published. Required fields are marked *