Shopping checklist
Install a prehung interior door
Half day · Moderate · 8 steps
Materials
| Done | Item | Quantity | SKU | Price |
|---|---|---|---|---|
| Prehung interior doorMatch the width, swing (L/H or R/H), and jamb width | 1 | Ask | ||
| 3/8 x 1-1/2 in wood shims | 2 bundles | Ask | ||
| 2-1/2 in finish nails | 1 lb box | Ask | ||
| 3 in trim screwsOne in each hinge, into the stud | 1 box | Ask | ||
| Passage knob or leverPrivacy set for a bedroom or bath | 1 | Ask | ||
| Door casingOnly if the old casing won't come off clean | 5 pieces, 7 ft | Ask | ||
| Wood filler | 1 small tub | Ask | ||
| White acrylic-latex caulk | 1 tube | Ask | ||
| Clear safety glasses | 1 pair | 641817001011 | $12.99 |
Tools
- 4 ft level
- Tape measure
- Hammer and nail set
- Flat pry bar
- Utility knife
- Drill/driver
- Oscillating tool or reciprocating saw
- Miter saw or miter box (for casing)
- Pencil
Before you start
- Wear safety glasses when prying out the old frame and nailing; old nails and finish nails both fly.
- A prehung unit is top-heavy and awkward. Get a helper to tip it into the opening, and keep the shipping clips on until the hinge side is fastened.
- Before cutting behind an old jamb, check the wall for wiring near the opening. Switches are often right beside a door.
- Keep fingers clear of the hinge side when you test the swing. A door closes with a lot of force at the hinges.
Prices are current as of printing and may change. Bring this list to the counter, or call (928) 669-9254. If we don't have it, we can order it.
Install a prehung interior door
Set a prehung interior door plumb and square so it swings smoothly and latches every time. The door comes already hung in its frame; your job is shimming it in straight.
- Time
- Half day
- Difficulty
- Moderate
- Category
- Around the House
- Steps
- 8
Before you start
- Wear safety glasses when prying out the old frame and nailing; old nails and finish nails both fly.
- A prehung unit is top-heavy and awkward. Get a helper to tip it into the opening, and keep the shipping clips on until the hinge side is fastened.
- Before cutting behind an old jamb, check the wall for wiring near the opening. Switches are often right beside a door.
- Keep fingers clear of the hinge side when you test the swing. A door closes with a lot of force at the hinges.
Step by step
- 1
Measure the opening and the swing
Pull the casing off one side and measure the rough opening between the studs. It should be about 2 inches wider and 2-1/2 inches taller than the door: a 30 inch door needs about 32 by 82-1/2 inches. Measure the wall thickness for the jamb width (4-5/8 inches for most 2x4 walls) and note the swing: stand where the door opens toward you, and the hinges are on your left for a left-hand door.
- 2
Remove the old door and frame
Pull the hinge pins and lift off the old door. Score the paint along the casing with a utility knife and pry it off gently if you plan to reuse it. Cut through the nails behind the old jamb with an oscillating tool or reciprocating saw, then pry the jamb out.
- 3
Check the opening
Hold a level against both studs and across the floor. If the floor is out of level, the latch side or hinge side of the jamb may need a little trimmed off the bottom so the head ends up level. Pull any old nails and clear debris so the new frame sits flat.
- 4
Set the door in the opening
Leave the shipping clips or nail that holds the door closed in place. Tip the unit into the opening with the hinge side against the correct stud, and center it so the jamb edges sit flush with both faces of the wall.
- 5
Shim and nail the hinge side
Slide pairs of shims in from opposite sides behind the jamb at each hinge, and at the top and bottom. Adjust them until the hinge jamb is perfectly plumb on both faces, then nail through the jamb and shims into the stud with 2-1/2 inch finish nails. Replace one short screw in each hinge with a 3 inch screw driven into the stud; it carries the weight of the door.
- 6
Shim the latch side and head
Remove the shipping clips and open the door. Shim the latch side so the gap between the door and the jamb is an even 1/8 inch from top to bottom, with a pair of shims right behind the strike plate. Close the door and check that it sits evenly against the stop, then nail through the shims. Shim the head only if it sags.
- 7
Trim the shims and test the swing
Score the shims flush with the wall using a utility knife and snap them off, or cut them with an oscillating tool. Open the door halfway and let go; a door hung plumb stays put. If it drifts, a hinge-side shim needs adjusting.
- 8
Install the casing and hardware
Nail the casing to the jamb and the wall framing, leaving a 3/16 inch reveal of the jamb edge showing. Install the knob or lever and the strike plate per the package, and adjust the strike so the latch catches firmly without rattling. Fill nail holes, caulk the casing joints to the wall, and paint.
Pro tip
Keep about a 1/2 inch gap under the door. Your heating and cooling need that path to move air back from closed rooms, and it matters even more in a house cooled by an evaporative cooler, which needs open air paths to work at all.