What Are Pre Hung and Slab Doors?

Bedrooms With Classic Hollow-Core Slab Doors
Bedrooms With Classic Hollow-Core Slab Doors. Steven Miric/E+/Getty Images

, When shopping for doors, you are encounter two entirely different types: slab and pre-hung. What is each type of door? How does installation compare to each other? 

Pre Hung and Slab Door Basics

  • Pre-Hung Door: This door comes already hanging in its own frame. It is a fully self-contained unit, complete with a door slab, hinges, and outer frame that fits into a prepared doorway. Not included: outer trim that blends the door in with the wall; doorknob or deadbolt; and strike plate.
  • Slab Door: This is a door and nothing else: no hinges, knobs, or frame. It is up to the buyer to attach to an existing door frame or to create a door frame. Mortises are usually not pre-cut; it is also up to the buyer to cut mortises.

Pre Hung Door Details

Scenarios and reasons that may compel you to buy a pre-hung door include:

  • New-Construction: No door has been installed in this location before. If the door frame is open and exposed, you will find it easier to install a pre-hung door than a slab door. The reason is that you would need to build the slab door's frame from scratch. While not a difficult task, it does add more work to your entire project.
  • Damage: If the existing door frame is so damaged or warped as to make it impossible to hang a slab door, it is usually easier to demolish that entire door area (frame included) and start from the beginning.
  • Installing an Exterior Door. Pre-hung doors come weather-tight off the shelf, with no need to do anything else to make them tight-fitting other than to install them properly. By contrast, unless you are highly experienced, it can be difficult to install a tight, weatherproof exterior slab door. Pre-hung makes this an easier--though not easy--process for DIYers.

    In some instances, you may want to avoid pre-hung doors:

    • When Heavy/Bulky Is an Issue: Pre-hung doors are very heavy and hard to manage. At around 60 to 100 pounds, a pre-hung interior door with a hollow core slab is the lightest pre-hung door you can buy.  Even if weight is not an issue, it is a bulky product to move around. Prehung exterior doors weigh over 100 pounds and need two strong people to move them. Also, if you have vehicle smaller than a truck or SUV, transporting a pre-hung door is difficult, if not impossible. 
    • When Your Carpentry Skills Are Not Great: Pre-hung door installation may seem like a slam-dunk but it is not. While you do not have to worry about the exacting task of hanging the slab to the frame, you still have the exacting task of fitting the pre-hung unit as a whole into the door opening. Pre-hung units, like all doors, require shimming. Even a pre-hung unit can be installed improperly so that swing and closing are impaired. Also, keep in mind that you still need to finish all of the work around it: drywall, painting, and installation of trim plus trim staining or painting.

    Slab Door Details

    You may want a slab door in scenarios like this:

    • When Saving Money Is Vital: Slab doors cost about three times less than pre-hung door units.
    • When You Want a Unique Style: Slabs provide you with much more design flexibility. For example, if you find an antique or unique door that you want to re-purpose for your own house, you can do so. These nearly always come in slab form, rarely as pre-hung units.
    • When Installing Only One Door: It may be beneficial to use pre-hung doors if you intend to install many doors. But if this is just one or two doors, you can afford to devote extra time to achieve a perfect installation.
    • When It Is an Exterior Door: Interiors are more forgiving environments for less-than-perfect installations, as weatherproofing is not an issue.

    Reasons you may want to avoid installing a slab door include:

    • If Carpentry Is Difficult For You: Slab door installation requires a steady hand, a good eye, and plenty of practice. It is easier if you are doing a one-for-one installation (a situation when the new door is the same size and configuration as the old door). But if there is any variation in door size and configuration, it will be difficult to make it hang right.
    • If You Are Using a Recycled Slab Door: If your building skills are shaky yet you still want to install a slab door, you may wish to use a new slab. It will be flatter and truer than a used door. Recycled slab doors may need extra attention (planing, sanding, straightening, etc.).

      Which Should You Buy?

      For exteriors, it is recommended that you install a pre-hung door. For interiors, you may wish to install a pre-hung door if this is an extensive remodeling project. If you are installing only one or two doors, then you may want to consider installing slab doors.