What’s a Prehung Door?
A prehung door comes with the door and hinges already installed in a frame. The frame includes the door jambs, or legs (the vertical elements), as well as the header that forms the top of the frame and connects the jambs. In a prehung door installation project, you install the entire assembly rather than just the door itself. When you choose a prehung door, you need to ensure that it’s set up to swing in the correct direction and that you’re able to install the lockset (the knob or handle) on the correct side.
While this type of door includes the frame, not all prehung doors include the casing, which is the trim or moulding that covers the gap between the frame and the wall. If you don’t purchase a door that includes the casing, you need to purchase the door casing separately and install it as well.
You can find prehung single doors, such as those you’d use for a typical bedroom, and prehung double doors, like those you might install at the entrance to a living room or a large walk-in closet.
Prehung Entrance Doors are Common Exterior Door Replacements
While you can find slab entry doors, prehung entry doors are often the best choice. The door is already installed in the frame, providing a good, weather-tight fit that’s difficult to accomplish with a slab.
What’s a Slab Door?
A slab door is simply a door by itself. It has no frame, hinges or other hardware. When you install a slab door, you either install it in an existing door frame or build a frame for it yourself. A slab door, sometimes known as a blank door, is more economical than a comparable prehung door.
Slab Doors Are Common Interior Door Replacements
In most cases, if you want to replace an interior door and the interior doorway is in good shape, you use a slab door. You can find slab doors predrilled for door hardware with a hole for the lockset and an inset for the latch, but often you have to bore the holes yourself when you install the door.
Whichever type of interior door you choose, you have lots of options. See our guide to interior doors to learn what’s available so you can find the right door for your home. Before you choose a knob or handle, take a look at our door hardware guide to learn about functions and finishes.
Comparing Prehung and Slab Doors
Prehung doors and slab doors are available in a similar range of materials. You have a similar selection of styles, designs and finishes to choose from. So aside from the construction, how do prehung doors and slab doors compare? In addition to cost, the installation process is significantly different.
Prehung Door Installation Overview
A prehung door can simplify installation in some ways. It’s typically predrilled for door hardware, and the frame is usually ready for you to install the strike plate. You don’t have to position and install hinges, and the door is already balanced and set to open and close properly.
Keep in mind, however, that a prehung door installation requires you to remove and reinstall the door casing and to remove the existing frame completely. A prehung door is heavier than a slab door so it’s awkward to maneuver. Moving and installing a prehung door is a two-person job, and you need to handle the assembly carefully to avoid damaging the frame. While you can expect the door to open and close smoothly, you need to make sure the frame itself is level and plumb. This usually involves using shims to adjust the assembly to the correct position and keep it in place as you install it.
To learn how to install or replace a prehung door in your home interior, take a look at the Prehung Door Installation section of our project, How to Replace a Door: Slab and Prehung Door Installation. To learn how to replace a prehung door on your home exterior, see our project, How to Install a Prehung Exterior Door.
You can find:
While hollow-core doors for interiors are lighter, solid-core doors have better insulation. Solid-core interior doors are also the best choice for rooms if noise is a concern.
Slab Door Installation Overview
While you don’t need to remove the casing and frame for a slab door, you have to precisely measure, mark and cut mortises for the hinges. If the door isn’t ready for the door hardware, you need to carefully measure for the lockset and latch and then bore the holes for the hardware. You might also need to trim the bottom of the door so it fits the existing door frame. However, a slab door will be easier to handle.
For step-by-step installation instructions, see the How to Replace a Door: Slab Door Installation section of How to Replace a Door: Slab and Prehung Door Installation.
When to Choose a Prehung or Slab Door
Personal preference, your do-it-yourself experience, and the time and effort you want to spend are all factors in choosing between these two types of doors, but there are some situations that make one a better choice than the other.
When to Choose a Prehung Door
- You’re doing a remodel and working with a rough door opening.
- The existing frame is damaged or not square.
- You want to replace the door casing or moulding for a new look.
- You have several doors to install.
- You’re replacing an exterior door.
When to Choose a Slab Door
- You’re replacing a single door, and the frame is in good condition.
- You’ve got an existing door you can use as a template for positioning hinges and other hardware.
- The doorway isn’t a typical size.
- You’re working on a limited budget.
- You don’t want to have to install the frame and casing.
- You want to be able to customize the door easily.