Deadbolt Lock Installation on a Door That Has None

Measure the door before you buy the lock

A lot of the half-finished jobs we get called to start the same way. The deadbolt was bought on a Saturday, the box was opened at the door, and only then did anyone notice the door was thicker than the lock allows, or the knob sat at a different backset.

A deadbolt lock installation is really a door preparation job. The lock has to suit the door, not the other way around, so these four numbers come first.

Thickness is the one that catches people out. Schlage's B60 product page lists doors up to 1-7/8", yet the B-Series instruction sheet stops at 1-3/4", so go by the instructions for the exact model. Doors heavier than that belong with commercial hardware such as the Schlage B600, which is built for 1-5/8" to 2" doors.

The two holes behind every deadbolt lock installation

A tubular deadbolt, the common bored type on residential doors, needs two holes drilled at right angles and two shallow recesses cut, one in the door edge and one in the frame. Here is what each cut does.

• Face bore (cross bore). A 2-1/8" hole straight through the face of the door. The outside cylinder and the inside thumb turn housing meet in it. Schlage's B-Series also accepts a 1-1/2" cross bore, but 2-1/8" is the size Schlage, Kwikset and Yale all share.
• Backset. The distance from the door edge to the center of the face bore: 2-3/8" or 2-3/4". Matching the knob's backset keeps the deadbolt directly above it.
• Edge bore. A 1" hole drilled into the edge of the door, centered on its thickness, until it breaks into the face bore. The bolt mechanism slides in here.
• Faceplate mortise. A shallow recess around the edge bore so the bolt's faceplate sits flush. Kwikset's 660 faceplate is 1" x 2-1/4". Yale specifies radius corners, so the recess shape has to suit the plate you bought.

Text version of this diagram

Door face: a 2-1/8 inch hole through the door, its center 2-3/8 inches from the door edge. The alternative 2-3/4 inch backset puts the hole slightly farther in.

Door edge: a 1 inch hole centered on the door thickness, meeting the face bore, with a shallow mortise around it for the bolt's faceplate.

Where the new deadbolt sits on the door

Height comes from the knob. Schlage's B-Series instructions and Yale's Everly spec both place the deadbolt center 5-1/2" above the center of the knob or lever. That spacing gives each lock room for its trim and lines the deadbolt up with matching hardware.

On a door with no knob to measure from, such as a door that will get a full handleset later, Kwikset's handleset drilling sheet puts its template centerline about 38" from the floor. That is a sensible reference, but the handleset's own template should always win.

Check what the hole will land on. On panel doors and doors with glass, a 2-1/8" bore at your chosen backset has to sit in solid door, not in a glass frame or a thin panel. If the glass is close enough for someone to reach through to the thumb turn, read our comparison of single and double cylinder deadbolts before choosing the lock.

How we drill and fit a new deadbolt

Every manufacturer's template is slightly different, so on each deadbolt lock installation we work from the one in the box rather than from habit. The order below stays the same on every door.

1. 01

   Mark from the template

   Tape the template at the agreed height and backset. Mark the face bore center and the edge bore center.

2. 02

   Bore the face

   Cut the 2-1/8 inch hole with a hole saw, finishing from the second side so the surface does not splinter.

3. 03

   Bore the edge

   Drill the 1 inch hole square to the edge and centered on the door thickness until it meets the face bore.

4. 04

   Mortise and mount

   Chisel the faceplate recess flush, fit the bolt, cylinder and thumb turn, then test with the door open.

5. 05

   Cut the strike

   Mark where the bolt meets the jamb, cut the pocket and recess, fit the strike, then test with the door closed.

The test that matters is the last one. With the door shut, the bolt should throw its full 1" and retract again without you pushing or pulling on the door. If it drags, Schlage's trick works well: rub chalk or lipstick on the bolt, lock and unlock, and the mark on the frame shows exactly where to trim.

Getting the frame side of a deadbolt lock installation right

The strike pocket is where a careful job and a rushed one part ways. Schlage support and Yale both say the pocket should be at least 1" deep, and Schlage's B-Series instructions ask for 1-1/4". A shallow pocket stops the bolt short, so it never reaches its full throw.

The screws matter too. Consumer Reports found that many locks come with short screws that only catch the thin jamb, not the framing behind it. Some deadbolts, such as the Schlage B60, include a strike reinforcer with 3" screws. If yours does not, ask about reinforcing the strike plate at the same visit, since the jamb is already open.

Doors that need a different plan

Most installs follow the standard prep. These are the cases where we change something before drilling.

• Thick doors. Anything over 1-3/4" needs a lock whose instructions list that thickness, or commercial hardware.
• Steel and fiberglass doors. Tell us the material when you book. The cuts are the same size, but the tools are not.
• Doors you may make smart later. Most smart deadbolts use the same 2-1/8" and 1" prep. The Schlage Encode Plus, for example, fits 1-3/8" to 1-3/4" doors at either backset, so the holes we drill now will suit a later smart deadbolt upgrade.
• A door that already has a deadbolt. That is a different job, because the holes exist. Our page on swapping out an existing deadbolt covers what has to match.

If you are unsure which style suits the door at all, our guide to the types of deadbolts walks through each one and where it is used.

What a deadbolt lock installation costs

Price depends on the lock you choose, the door material, whether the frame needs repair and how many doors are done in one visit. After-hours work costs more than a scheduled weekday slot.

As one reference point, Locksmith Ledger's 2024 reader survey (not a scientific survey) put average locksmith labor at $104 an hour during regular hours and $151 after hours. Typical national figures vary by location, and our deadbolt installation cost guide explains how quotes are built.

A two-minute door check before you call

Measure the door thickness across the edge and the knob backset from the edge to the knob center. Take one photo of the door edge and one of the frame where the bolt will go, and note whether the door is wood, steel or fiberglass.

With those three details, we can tell you before the visit whether a standard deadbolt will fit or the door needs heavier hardware, and the deadbolt lock installation becomes a single trip.