Prehung vs. Slab Doors: Which Is Right for Your Remodel?

Once you decide to replace interior doors, this is the next question, and it has a real answer that depends on your walls rather than on preference.

The two options

A slab is just the door. You reuse the existing jamb, casing, and hinge locations, mortise the new door for hinges and hardware, and hang it.

A prehung unit is the door already hung in a new jamb, with hinges mortised at the factory. You remove the old door and the entire frame, set the new unit plumb and level, shim it, fasten it, and case it.

Slabs: cheaper material, more skill

Slabs cost less and generate less waste. The catch is that everything has to match the frame you are keeping.

The new door has to be the same size, and doors were not always ordered in standard sizes, especially in older or custom homes. Hinge locations have to be mortised to match exactly. If your existing hinges are a different size or radius, that adds work. And critically, the door will only hang well if the existing jamb is still plumb and square.

Slab work is more skilled labor and less material. On a house with good frames, it is the smarter buy.

Prehungs: more material, faster and truer

A prehung fixes the frame problem, because you are replacing the frame. The unit arrives square from the factory, which means the reveals around the door will be even and the latch will meet the strike.

It costs more per opening in material, and it requires new casing on both sides, plus drywall touch-up where the old casing came off. But installation is faster and the result is more predictable in a house that has settled.

If you are already replacing casing throughout, which most whole-home packages do, much of the extra prehung labor disappears, since the casing was coming off anyway.

How to tell which one your house needs

Do this yourself in ten minutes with a level.

Open a door halfway and let go. If it swings open or closed on its own, the jamb is out of plumb. Check the reveal, meaning the gap between the door and the jamb, along the top and the latch side. It should be even. If it tapers, the frame has moved. Look at where the latch meets the strike plate, since a strike that has been filed out or a door you have to lift or shove is a frame problem. Put a level on the hinge jamb in both directions.

If several doors fail those checks, the house has settled and prehungs will save you fighting each one. If the frames are true, slabs are the better value.

Mixed answers are common and fine. We regularly hang slabs on the good openings and set prehungs where the frames have moved.

Other things that push the decision

Going from hollow-core to solid-core adds weight, and an old jamb with hinge screws only in the jamb will sag under it. If you keep the jamb, hinge screws get replaced with long screws into the framing.

Changing door swing, changing size, or converting a door to a cased opening all mean framing work regardless.

If you want a different jamb profile or a wider casing reveal, prehungs give you a clean starting point.

If flooring was installed after the doors and the undercut is now wrong, the door may need trimming, which is easy on a slab and easy on a prehung too, but worth catching in advance.

Cost and schedule

Slabs on true frames are the lowest-cost path to new doors. Prehungs with new casing cost more per opening and deliver a more uniform result.

Either way, the work lands inside our interior doors and trim range of $2,000 to $12,000, depending on door count and how much casing and base come with it. A 14-door house done in slabs with existing casing sits toward the lower half. The same house in solid-core prehungs with upgraded casing and taller base throughout sits near the top.

Disruption differs too. Slab work is quieter and the openings stay framed the whole time. Prehung work means open doorways and drywall touch-up.

What we usually recommend

Check the frames first, honestly, opening by opening. Reuse what is true and replace what is not. Upgrade to solid-core where people sleep and work. And if you are touching the casing anyway, that is the moment to go prehung on the problem openings, because you will never have a cheaper opportunity.

Holland & Sons Construction is family-run and led by 35 years of hands-on carpentry experience. Brian Holland with his sons Wyatt and Waylon. CSLB #1123738, B General Building. We serve Menifee, Temecula, Murrieta, Corona, Norco, Riverside, Wildomar, Winchester, Eastvale, Lake Elsinore, and Moreno Valley.

If you want us to check your frames and give you a real number, call (951) 338-8058 or start a conversation.