Slab vs. pre-hung: the two ways to replace a door
The cheapest swap is a slab door — just the door panel — reused in your existing jamb. If the new slab is the same size and your old frame is still square and solid, a slab install runs roughly $150 to $400 including labor, because the installer reuses the frame, hinges-mortises, and casing. The catch: the new slab must be mortised for hinges and bored for the handle to match the old layout, and that only works when the existing jamb is in good shape. A pre-hung door comes as a complete unit — slab already hung in a new jamb with hinges set — and runs about $350 to $600+ installed for a standard interior door, more for solid-core or wider sizes. Pre-hung is the right call when the old frame is damaged, painted shut, or so far out of square that no slab will close evenly in it.
What actually drives the price up
Four things move the number. Door type: a hollow-core builder-grade panel is the floor; a solid-core door (much quieter, heavier, better for bedrooms and offices) costs noticeably more in both material and labor, and a 5-panel, French, or barn-style door costs more again. Casing and trim: if you want new casing to match a remodel, that adds material and finish-carpentry time over reusing existing trim. Hardware: new levers, hinges, and a bored hole all add up across a whole house. And the opening itself — in older Utah homes, openings have racked out of square as the house settled, so the installer spends extra time shimming the jamb plumb and re-cutting reveals. Removing and hauling the old door typically adds a small amount per opening.
Why older Utah homes cost more to do right
Homes across the Wasatch Front that were built decades ago — and even some newer ones on expansive clay soils — settle, and that settling racks door openings out of square and out of plumb. You can spot it from a door that drifts open or won't latch without a shove. A lazy install ignores this: the jamb gets nailed straight to a crooked rough opening, the door binds at the top corner, and the gap (the reveal) around the door is fat on one side and tight on the other. Doing it right means setting the jamb plumb and level independently of the crooked wall, packing the gaps with shims behind every hinge and the strike, and tuning the reveal so it's even top to bottom. That extra labor is the real reason quotes vary on identical-looking doors.
What a properly hung door looks like
A correctly hung interior door sits plumb in its frame, swings without drifting open or closed on its own, latches with a light pull, and shows an even reveal — the gap around the slab — of roughly an eighth of an inch on the top and both sides. When those gaps are uneven, the door rubs the jamb, the latch misses the strike plate, or you see daylight at one corner. Getting there isn't about the door you buy; it's about the install: shimming the hinge side dead plumb first, hanging the slab off it, then setting the strike side to a consistent reveal and confirming the door holds position anywhere you stop it. A solid-core door also wants tight, even gaps to deliver the quiet it's built for.
What Wasatch Finish does on door work
Wasatch Finish handles interior door replacement and installation as non-structural finish work — slab swaps, pre-hung interior doors, closet and pocket-style doors, plus new casing, trim, jamb shimming, hardware, and the fit-and-finish that makes a door sit plumb with even reveals. We're licensed under Utah DOPL R101 for non-structural projects under $50,000, which covers door and trim work cleanly, including doors added during a basement finish or bathroom remodel. What's outside that scope: we don't cut new structural openings into load-bearing walls or alter framing that carries load. If your project needs a new opening framed into a bearing wall, that structural portion is coordinated with or referred to the appropriate licensed trade, and we do the interior finish around it — door, jamb, casing, hardware, and paint.
Bottom line
Budget about $200-$600 per interior door installed in Utah — slab swaps are cheaper, pre-hung units cost more but fix bad frames. In older, settled homes the real cost is the labor to shim the jamb plumb and dial in even reveals so the door actually closes right.
Questions
How much does it cost to replace an interior door in Utah?
Replacing an interior door in Utah costs roughly $200 to $600 per door installed, depending on the type. A slab-only swap into a good existing frame runs about $150 to $400, while a complete pre-hung unit with a new jamb runs about $350 to $600 or more for solid-core or oversized doors. Whole-house quotes drop the per-door price because the installer mobilizes once and works through openings in sequence.
Is a pre-hung door or a slab door cheaper to install?
A slab door is cheaper to install than a pre-hung door, because it reuses your existing frame, hinges, and casing — typically $150 to $400 versus $350 to $600+ for a pre-hung unit. But a slab only works when the old jamb is square, solid, and the right size. If the frame is damaged, painted shut, or has settled badly out of square, a pre-hung door is the better value because it solves the frame problem in one step.
Why won't my interior door close or stay shut?
An interior door that won't close, latches poorly, or drifts open on its own is usually hung out of plumb, often because the opening settled out of square — common in older Utah homes. The fix is re-setting the jamb plumb with shims behind the hinges and strike, then tuning the reveal so the gap around the door is even. Sometimes the strike plate just needs adjusting; other times the whole jamb needs to be reset. A new slab in a crooked frame won't fix it on its own.
What's the difference between a hollow-core and solid-core interior door?
A hollow-core door has a light frame around an empty interior, while a solid-core door is filled with a dense material, making it heavier, sturdier, and much better at blocking sound. Solid-core doors cost more in both material and labor but are worth it for bedrooms, offices, and bathrooms where quiet and privacy matter. Hollow-core is fine for closets and lower-traffic openings where sound isn't a concern.
Does Wasatch Finish handle door installation as part of a basement or bathroom project?
Yes — Wasatch Finish installs interior doors as part of basement finishing, bathroom remodels, and standalone door work, all within our Utah DOPL R101 non-structural scope under $50,000. That includes pre-hung and slab doors, closet and pocket-style doors, new casing and trim, jamb shimming for square reveals, and hardware. If a project needs a new opening framed into a load-bearing wall, that structural part is coordinated with the appropriate licensed trade while we complete the interior finish.