Hang Interior Doors
Install prehung interior doors that open smoothly, close securely, and add privacy and functionality to your finished basement rooms.
Why Proper Door Installation Matters
A properly hung door operates smoothly for decades. An improperly installed door binds, scrapes, won't latch, or swings on its own - constant frustration that diminishes your basement's usability. The key is getting the door jamb perfectly plumb (vertical) on the hinge side. Everything else adjusts from there. Prehung doors simplify installation dramatically, arriving with jamb, hinges, and often pre-drilled for hardware. Taking time to shim and level correctly during installation prevents problems and creates doors that function flawlessly.
Tools & Materials Needed
Step-by-Step Guide
Check Rough Opening
Verify opening is correct size before unpacking door:
- •Measure width: Should be 2 inches wider than door unit (38.5" for 36" door)
- •Measure height: Should be 1 inch taller than door unit (82.5" typically)
- •Check corners with framing square - should be reasonably square
- •Ensure floor is flat and level across opening
- •Remove any debris or protruding nails from opening
Prepare and Set Door Unit
Unpack and position prehung door in opening:
- •Remove packaging but leave temporary braces holding door closed
- •Note swing direction - hinges should be on correct side for room layout
- •Set unit into opening with helper - doors are awkward and heavy
- •Center unit in opening with equal space on hinge and latch sides
- •Place temporary shims under jamb legs to support weight
Shim and Level Hinge Side
Getting hinge jamb plumb is most critical step:
- Place level against hinge-side jamb, check for plumb
- Insert shim pairs behind each hinge location, adjusting until plumb
- Add shim pair at top and bottom of hinge jamb for support
- Recheck plumb - adjust shims as needed
- When perfect, drive one nail through jamb and shims at middle hinge
- Open door slightly and verify it stays in position (doesn't swing)
Critical: Hinge jamb MUST be perfectly plumb or door won't hang correctly. Take your time on this step.
Shim and Secure Latch Side
Adjust latch jamb to ensure consistent gap and proper latching:
- •Close door and check gap between door and jamb - should be consistent (about 1/8")
- •Insert shims at strike plate location, adjusting until gap is even
- •Add shims at top and bottom of latch jamb
- •Nail through jamb and shims at each shim location with 2.5" finish nails
- •Complete nailing hinge jamb at all shim locations
- •Test door operation - should swing freely and latch without forcing
Install Hardware and Finish
Complete installation with hardware and trim:
- •Score protruding shims with utility knife and snap off flush with jamb
- •Install doorknob/lever according to manufacturer instructions
- •Install strike plate, ensuring it aligns with latch bolt
- •Install door stop molding if not already attached
- •Test door multiple times - open, close, latch, unlock
- •Install door casing trim (covered in separate step)
Pro Tips
- ✓Use a 6-foot level for more accurate plumb readings on tall doors
- ✓Test door operation after each nail - easier to adjust before all nails are in
- ✓Standard bedroom/bathroom doors are 30-32 inches, main doors are 36 inches
- ✓Pre-drill nail holes in hardwood jambs to prevent splitting
- ✓Keep temporary braces on door until fully nailed to prevent warping
Frequently Asked Questions
What size rough opening do I need for a 36-inch door?▼
For a 36-inch prehung door, frame a rough opening 38 inches wide by 82.5 inches tall. This provides space for the jamb (which adds about 1 inch per side) plus shimming room. Standard door heights are 80 inches, and the jamb plus header brings total unit height to about 81.5 inches. Always verify dimensions with your specific door unit before framing.
Should I install doors before or after flooring?▼
Install flooring first, then hang doors. This ensures proper clearance between door bottom and finished floor (typically 1/2 to 3/4 inch). If you install doors first, you risk improper clearance when flooring is added. Exception: If using thick flooring, you may need to trim door bottoms after installation, or order taller doors.
How do I know if my door is hung correctly?▼
A properly hung door: swings freely without binding or scraping, stays in position when opened (doesn't swing on its own), latches easily without forcing, has consistent gap (reveal) around all edges, and is plumb (vertical) on the hinge side. Use a level to check plumb and test door operation before final nailing.
Can I reuse old doors or should I buy prehung?▼
For DIYers, prehung doors are strongly recommended. They come with jamb, hinges, and often pre-drilled for hardware, making installation much easier. Hanging a slab door (just the door, no jamb) requires building a jamb, mortising hinges, and precise fitting - skills that take practice. Prehung units cost $50-100 more but save hours of work and frustration.