There are some quick and obvious benefits of selecting a prehung door. Prehung doors, as the name suggests, come pre-attached to the corresponding frame.
The biggest benefit of a prehung door is that the hardest work is already done for you. The hinges are mortised, the lockset is bored, and the jambs and stops are pre-fitted. Basically, prehung doors greatly reduce the likelihood that you'll have to spend hours tweaking and adjusting or working to eliminate binding hinges, sticking, and that all too common door squeak.
While available in exterior and entry options, prehung doors are most commonly installed inside. This article will focus on hanging a prehung interior door.
|Tools||Materials||Skill Level||Estimated Time|
|• Levels (2-, 4-, 6-foot)||• Prehung door (LH or RH)||Intermediate||Less than 4 hours|
|• Circular saw||• Shims|
|• Squares (carpenter’s square and speed square)||• Finish nails (4d, 6d, 8d)|
|• Hammer||• Lockset|
|• Utility knife (or handsaw)||• 2 ½” #9 screws (matching hinge finish)|
|• Nail set|
|• 4-in-1 file|
|• Drill driver and 3/32" drill bit|
|• Phillips head screwdriver (#2)|
|• Slotted screwdriver|
|• Trim puller (also known as a molding bar or small pry bar)|
|• Nail pulling pliers|
Follow the steps below to install a prehung door.
Prepare the Install
Interior prehung doors can be found in many options including solid wood (commonly birch) or hollow core and with or without a raised panel detail. The hollow core door, the most common, is both stable (in terms of expansion and contraction) and light weight, but will not offer soundproofing like traditional solid wood paneled doors. They can come finished with a variety of wood-like materials.
1. Are You Ready to Install?
Prior to beginning your installation, your door opening should be framed and your surrounding walls should be finished (i.e. drywalled and painted, in most cases). A new "rough" door opening should be framed at a dimension two inches wider and two inches taller than your selected door size.
It may or may not be installed before a finished floor. If you have yet to install the finished floor (which is often the case with full room remodels), you might want to pay attention to the “build up” new flooring will create and consider it when preparing to hang your door.
2. Purchasing Your Door
The most common door size is likely 2/8 x 6/8 (spoken as "two eight six eight," which means two foot eight inches wide by six foot eight inches tall or 32" x 80"). Customizations in size can be made during ordering, but selecting a door that is the correct size for your “rough opening” will save you a headache during installation later.
Right-Hand or Left-Hand?: Think of it this way--most doors swing into a room. When standing on the outside of your door opening, and thinking about which way you want your door to swing, ask yourself: Are the hinges on the left or on the right? If the hinges are on the left, it's a left-handed door and this is what you will need to order (Remember locksets are pre-bored and hinges pre-installed so it is important to get it correct). If the hinges are on the right, you are instead looking for a right-handed door.
Tip! Alternatively, place your back against the jamb where you want the door to hinge. Swing your arm up in the direction you want the door to swing. If you raise your left arm to simulate the door swing, it's a left-handed door. Right, well, you get it--a right-handed door.
3. Unpacking your Door
Prehung doors are shipped and sold stapled shut. Before you can begin your installation, you'll need to unpack your door. This typically does not require more than removing a strip of scrap lumber that attaches the door to the door's framing. You'll also likely find a "plug" holding the door to the frame at the latch bore. Prying these away with a flat-head screwdriver will typically work just fine.
4. Prepping the Door and Frame
In more cases than not, your door’s frame will come pre-fitted with trim. It is usually easiest to remove it completely before beginning installation. Do this using a trim puller (also known as a small pry bar) paired with a nail puller.
Warning: Work carefully here as not to damage the trim. Set it aside in a safe place for use later.
Before we begin our installation we will also remove the door. Take your nail punch and starting at the bottom of the hinge, tap the hinges’ pins upward and out, ultimately uncoupling the hinges. Set the door aside in a safe place.
5. Rough Fit the Door Frame into the Opening
The purpose of this step is to simply ensure that your new door, with its frame, will fit. If you determine that you need to cut any of the height from the doors’ jambs, do so using a circular saw. Remember that the unit’s jamb stock will be roughly 3/4" thick, and you always want about a half inch between the back of the jamb and your framing. This will allow you to play with square and plumb during the installation process.
7. Setting the Jamb
The frame’s jambs, in their most common off-the-shelf form, are 4 1/2" wide. This syncs nicely with a 2x4 framed wall and two sides of 1/2" drywall (3 1/2" + 1/2" + 1/2" = 4 1/2").
After you’ve made cuts (if needed) and have determined your starting point, you’ll reset the door frame into your opening. Line up the jamb, centered to your finished wall(s) (a carpenter square can come in handy for this purpose--“wrapping it around the corner”).
You will begin nailing on the hinge-side jamb at the point furthest into the opening (this, by the way, may only amount to a fraction of an inch). You start by nailing directly to our (jack) stud in this location--two 8d nails about three inches down from the top (or head) jamb.
8. Plumbing the Hinge Jamb with Shims
Pair the shims, inserting one from each side of the wall, and oppose them so that they line up perfectly. You will be placing them immediately behind each of your hinge locations.
Note: Some doors come with two hinges, others with three.
Install two 8d nails above the hinges (and consequently, above the shims). Additional shim pairings should be added halfway between the initial shim locations at the hinges, and at intervals no closer than 12". These “midpoint shims” will have nails driven directly through them later. The key here is not to "overdrive" your shims, simply making sure that they are snug in place. Frequently check that the hinge-side jamb is plumb and square as you work. Drive all nails just flush to the jamb, but do not fully set them at this point.
9. Re-Hang the Door and Shim the Latch or Lockset Jamb
Re-install the door using the hinge pins provided. Simpler than shimming the hinge jamb, you will place (at minimum) three sets of shims on the latch-side jamb. One set should be placed immediately behind the point where the lockset strikes the jamb, while others will be set across from your hinge locations. Pre-drill nail locations and drive two 8d nails through each set of shims. Check the gap between the closed door and the jamb (1/8" spacing is ideal), it should be equal from the top to the bottom of the jamb. Set these nails with your nail set.
Shim (if necessary) and nail the head jamb in three locations.
10. Install the Lockset
Follow your manufacturer’s instructions and install your selected lockset.
6. Check Plumb of the Rough Framing
Plumb is level in the vertical direction. Use a 6-foot or a 4-foot level to determine whether framing is plumb. If you find that your framing is not plumb, and it may not be, identify which point on the hinge-side framing (top or bottom) sticks out into the opening. Don’t worry, you can easily adjust plumb of the door with your shims, it’s simply a matter of identifying the starting point for your install.
Important! The most important aspect of installing your door is installing it absolutely plumb (and square) on the hinge-side. If you do not, your door may swing unwantedly open or closed.
The Finishing Touches
11. Inspect and Complete the Door Installation
If your door is operating with ease, latches when closed, and isn’t swinging open or shutting on its own, set a single 8d through each of your hinge-side shims. Again check for plumb, and set your hinge-side nails with your nail set.
Once you are satisfied with the fit of your door, cut the excess from your shims, bringing them flush with the plane of your finished wall on each side. You can use either a hand saw or a utility knife to accomplish this task.
12. Re-install Your Door Casing
Establish a consistent reveal on your jamb and use both 6d and 4d nails as they make sense to complete this installation.
Bonus Tip: Replace one or two screws in each hinge with a screw that is long enough to catch the hinge-side (jack) stud. This usually means employing screws that are 2 1/2" long.
Level of Difficulty
Considerably easier than installing a door in parts (hanging the jamb and stops and mortising for hinges, boring for locksets, etc.), let’s call this a low-level intermediate project.
“Split-jamb” prehung doors are available and may make the installing several doors within the scope of a project even easier. This installation method, however, would have to be addressed in an additional tutorial. Good luck.
Find a Pro
Do you need help installing your prehung door? Call on a trusted Redbeacon Pro! Each Redbeacon Pro is background-checked, licensed, insured, and fully bonded so you can hire with confidence. Always be sure to read each Pro’s exclusive customer reviews, verify Pro credentials, and compare business profiles before selecting the right Pro for the job. Ready to get started? Contact a Redbeacon Pro to get started on your prehung door installation.