A poorly installed interior door sticks, rattles, or just looks off. But get it right, and it closes smoothly, lines up perfectly, and adds a polished touch to any room.
Whether you’re replacing an old door or putting in a new one, the key is precision—measurements, alignment, and securing everything properly.
We’ll walk you through every step, so your door fits and functions exactly as it should.
Key Notes
- Measure the door opening carefully to ensure a proper fit.
- Use shims to keep the frame level and plumb during installation.
- Secure hinges and hardware correctly for smooth door operation.
- Check alignment and make final adjustments before sealing and finishing.
- Reinstall or replace trim for a clean, polished look.
1. Gather Necessary Tools and Materials
Having everything ready before you start will save time and frustration. Here’s what you’ll need:
Tools:
- Measuring tape
- Level
- Screwdriver or drill
- Hammer
- Chisel
- Circular saw (if trimming is needed)
- Utility knife
- Pry bar
- Safety glasses and gloves
Materials:
- Pre-hung door or slab door
- Hinges
- Screws
- Shims
- Wood filler
- Sandpaper
- Paint or stain
- Caulk
- Door handle and lockset
2. Remove the Existing Door (If Replacing One)
If you’re swapping out an old door, you’ll need to remove it carefully to avoid damaging the frame or surrounding walls.
Detach the Door
Place a wedge or block under the door for support. Use a screwdriver or drill to remove the hinge pins, starting from the bottom.
Once the pins are out, lift the door off the hinges and set it aside.
Remove Trim and Frame (If Necessary)
If you’re replacing the frame as well, use a pry bar to carefully remove the trim. Work slowly to prevent damage to the wall.
Then, take out the old frame by loosening any screws or nails securing it.
3. Prepare the Door Opening
A properly prepped opening ensures the new door fits correctly and functions smoothly.
Inspect the Frame
Check the existing frame for damage, warping, or loose sections.
If it’s in good condition, you can install a new door without replacing the frame. If not, replacing the frame may be the better option.
Measure the Opening
Take accurate measurements of the height, width, and depth of the doorway. Compare these to your new door’s dimensions, ensuring there’s enough clearance on all sides.
Check for Level and Square
Use a level to confirm that the floor, sides, and top of the opening are straight. If adjustments are needed, use shims to correct any uneven areas.
4. Fit the New Door
With the opening ready, it’s time to position the new door.
Trim the Door (If Needed)
If the door is slightly too tall or wide for the opening, mark the excess and trim it using a circular saw. Sand the edges for a smooth finish.
Mark Hinge Positions
Place the door inside the frame and mark where the hinges will go. Use the old door as a guide if you’re replacing one.
Chisel Hinge Mortises
Use a chisel to create shallow recesses where the hinges will sit, ensuring they’re flush with the door edge.
Attach Hinges to Door
Secure the hinges onto the door using screws, making sure they’re aligned properly.
5. Install the Door
Now that the door is prepped, you can install it in the frame.
Position the Door
Set the door inside the frame, using shims at the bottom to hold it in place.
Secure Hinges to Frame
Fasten the hinges to the frame using screws, starting with the top hinge. Check alignment as you go.
Check for Proper Fit
Open and close the door a few times to make sure it moves smoothly and sits evenly. Adjust if necessary.
6. Install Hardware
With the door in place, it’s time to add the handle, lockset, and any other hardware.
Mark Hardware Placement
Measure and mark where the handle and lockset will go. If the door doesn’t have pre-drilled holes, you’ll need to drill them yourself.
Drill Necessary Holes
Use a hole saw or drill bit to create openings for the handle and lock.
Attach Hardware
Secure the handle and lockset according to the manufacturer’s instructions, ensuring everything is tight and functional.
7. Final Adjustments and Finishing
Before calling the job done, make sure everything is properly aligned and finished.
Adjust Door Alignment
If the door rubs against the frame or doesn’t close properly, adjust the hinges slightly or use shims behind the frame to tweak alignment.
Reinstall or Replace Trim
If you removed trim earlier, reinstall it now. If you’re using new trim, cut it to size and secure it around the frame.
Seal and Paint
Apply caulk along the edges of the trim for a clean, seamless look. Then, paint or stain the door and trim to match your room’s style.
Struggling With Misaligned Doors & Frustrating Gaps?
Frequently Asked Questions
Can I install an interior door without a frame?
Yes, but you’ll need to create a proper frame using casing and shims to ensure stability
What’s the standard gap between the door and the floor?
Typically, a ½-inch gap allows clearance for airflow and prevents rubbing on carpets or flooring.
How do I fix a door that swings open or closed by itself?
This usually means the frame isn’t plumb. Slightly adjusting the hinge screws or using shims can fix it.
Should I paint or stain the door before or after installation?
Painting or staining before installation is easier, but touch-ups may be needed once it’s in place.
How can I make an interior door more soundproof?
Use a solid-core door, apply weatherstripping around the edges, and install a door sweep at the bottom.
What’s the best way to remove an old door without damaging the trim?
Score the paint or caulk around the trim with a utility knife before prying it off carefully.
Conclusion
A well-installed interior door isn’t just about looks—it needs to fit right, swing smoothly, and close properly. Getting the measurements right, securing the frame correctly, and making small adjustments along the way all add up to a door that functions the way it should.
Take your time, check your work, and you’ll get a clean, professional finish.
Want it done quickly and flawlessly? Book a free appointment today.
