Interior door installation, by the houseful

What is interior door installation?

Interior door installation means fitting the doors between rooms - bedroom, bathroom, closet, hallway. The choice is between a slab, which is just the door hung in the frame you already have, and a pre-hung unit, which replaces the frame too. A single slab in a sound frame is genuinely a DIY afternoon. The job most people hire for is the other one: replacing every door in the house at once, with matched styles, matched hardware and new casing.

Signs you need interior door installation

• The doors are hollow-core flush panels from an earlier decade and every one of them looks it
• You can hear normal conversation clearly through a closed bedroom or bathroom door
• Several doors have been planed, packed or rehung over the years and none of them latch the same way
• The frames are sound but the doors are damaged - dents, holes, delaminated skins - which is the classic slab-replacement case
• Openings in an older house are non-standard sizes and every off-the-shelf door needs trimming

Seeing something not on this list? Browse doors problems by symptom →

How interior door installation actually works

1. 1

   Counting, measuring and sizing every opening

   On a whole-house job the installer measures each opening for width, height and jamb depth, records the handing and swing, and flags which are standard sizes and which need a custom or trimmed door. Pre-1960s houses routinely have several that are not standard anything.

   Watch forA price quoted per door before the openings have been counted. Two or three non-standard openings change the material bill and the lead time significantly.

2. 2

   Deciding slab or pre-hung, opening by opening

   This is not one decision for the house. Where the frame is plumb, square and undamaged, a slab is faster, cheaper and leaves the casing alone. Where the frame is racked, out of alignment, or the wrong depth for the wall, a pre-hung unit is the honest answer.

   Watch forA blanket recommendation either way. All-pre-hung inflates the bill and tears off casing that did not need to come off; all-slab hangs new doors on frames that were the problem.

3. 3

   Core choice - where solid-core actually earns its money

   Hollow-core is light, cheap and fine for closets. Solid-core is substantially heavier, deadens sound noticeably, and is the single upgrade most homeowners say they can feel. Solid wood is heavier still and moves with humidity.

   Watch forSolid-core doors hung on the existing lightweight hinges. The extra weight needs three hinges and screws into the framing, not two hinges and a hopeful jamb.

4. 4

   Hanging, shimming and the self-swinging door

   Each door is shimmed plumb behind the hinges and at the strike, and the reveal is set even down both sides and across the top. Shimming behind the hinges is what stops a door drifting open or shut on its own.

   Watch forDoors that swing themselves closed after the crew has left. That is a plumb error, and it is much cheaper to correct before the casing is nailed on.

5. 5

   Casing, hardware and finishing

   Casing is fitted or reused, hardware is set at a consistent height throughout the house, and every door is cycled and adjusted. On a whole-house job the value is in the consistency - the same lever, the same height, the same reveal on every opening.

   Watch forMixed handle heights and mismatched hinge finishes across the house. Individually invisible, collectively the thing that makes the job look amateur.

What does interior door installation cost?

Interior doors are the cheapest doors in the house - a hollow-core slab is inexpensive and a pre-hung unit modest. The number that matters on a whole-house job is per opening installed, commonly $150 to $600, with solid-core, custom sizes and new casing pushing toward the upper end.

See the full interior door installation cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →