The lock is one part of a small system
When people picture a lock installation, they picture the lock. In practice, the lock is one of four partners. The door holds the lock. The bore holes receive it. The latch or bolt moves out of the door edge. The strike plate, set into the frame, receives the bolt.
If any one of the four is off, the whole system suffers. A good lock on a poorly prepared door will stick. A well fitted lock with a misaligned strike will drag or rattle. A strong bolt that meets a thin frame will not stop a determined push.
This is why installation deserves its own page. Buying a lock is the easy part. Setting it so it works every day for years takes care. The steps below follow the order a careful installer works in, and they will help you understand what you are paying attention for when the van is in your driveway.
If the lock you want to replace is failing, our broken lock repair page helps you decide between repair and replacement.
Reading the door before touching it
The first act is to look. A door carries clues, and the locksmith reads them before any tool is picked up.
What material is the door? Solid wood, hollow core, steel, fiberglass, aluminum frame glass, each accepts hardware differently. How thick is it? Standard exterior doors are a common thickness, but older homes and custom doors vary. Is it hung true? Close it gently and look at the gaps around the edge. Even gaps mean a well hung door. A wide gap on one side and a tight one on the other means trouble that a lock cannot fix.
What hardware is already there? The existing holes tell you what size the new lock must be. If the new lock needs larger holes, the door needs boring. If the old holes are larger than the new lock needs, a cover plate or an adapter may be required.
Finally, what does the door do? A front door that sees heavy daily use needs different hardware from a shed door used twice a year. Match the lock to the job.
Door preparation: bore holes and the edge
Most residential locks need two holes in the door. A large hole through the face holds the cylinder or the knob and handle hardware. A smaller hole through the edge holds the latch or bolt. The two holes must meet at a precise point, because the mechanism inside has to connect through them.
The usual hole layout follows common standards, which is why a replacement lock often fits an existing door without new boring. When a door is new, or when the lock type changes, new holes may be needed. They are cut with proper hole saws and drill guides, not freehand. A hole cut crooked leads to a lock that binds.
The edge of the door also needs a recess, called a mortise, for the faceplate of the latch or bolt. The faceplate sits flush with the edge. A faceplate set too deep, or too proud, or crooked, causes trouble. Wood doors may need the recess cut and cleaned with a chisel. Steel doors usually come with the recess ready.
If a door has been drilled badly before, or is cracked around the hole, repair of the door comes first. A reinforcing plate can strengthen the area around the lock.
- Measure the door thickness before choosing the lock.
- Check that the cross bore and the edge bore meet at the correct point.
- Cut the faceplate recess so the plate sits flush.
- Repair cracked or oversized holes before fitting hardware.
- Reinforce the lock area on older wood doors if needed.
Deadbolts, handle sets and what goes where
A typical entry door has two locks. A spring latch, built into the handle or knob, holds the door shut against wind and casual push. A deadbolt, a heavier bolt thrown by a key or a thumb turn, provides the real security. The two do different jobs, and you want both.
The deadbolt is the more important in a break in. A good bolt extends a full length into the frame, and the strike plate holds it there. A short bolt, or a bolt that only half reaches its hole, offers much less. The installer checks the throw, which is how far the bolt extends, and confirms it enters the strike fully.
Single cylinder deadbolts have a key outside and a thumb turn inside. Double cylinder deadbolts need a key on both sides. Each has uses. The double cylinder resists reaching through a broken window, and it can trap people if a key is not nearby in a fire. Safety rules for doors vary, so ask about what is allowed or advisable in your building. We do not state codes here.
Our home locksmith page covers the wider range of residential lock work.
Strike plates: where the lock meets the frame
A strike plate is a small metal plate set into the door frame. It has a hole for the bolt and a ramp for the latch. It looks minor, and it is one of the most important parts of the system.
The strike holds the door shut when someone pushes. The screws that hold it into the frame decide how much force it can take. Short screws that reach only the thin trim give almost no strength. Long screws that pass through the trim and bite into the solid framing behind it give much more. A careful installer uses long screws at the strike and the hinges for this reason.
The hole in the frame behind the strike must be deep and clean. A bolt that reaches a shallow hole, or a hole packed with old paint, will not seat. The plate must also sit flush with the frame. A plate that stands proud catches the door. A plate set too deep lets the door rattle.
A reinforced strike plate, with a longer body and more screw holes, strengthens the weakest point of many doors. It is a modest change with real benefit.
The frame itself matters as much as the plate. A frame that is cracked, split along the grain, or soft with age will not hold even a good strike. In that case the frame section may need to be repaired or reinforced before the new lock goes in. A locksmith should point this out plainly and show you what they found, so you can decide with the facts in front of you.
Garage entry doors and back doors deserve the same attention as the front. They are often hidden from the street and are tested more often than people expect. Fit them with the same care, and tie them into your key plan so you do not carry a ring of unrelated keys.
Alignment: where most problems begin
Alignment means that the bolt and latch hit their holes in the strike without rubbing. It sounds simple. It is where most installation trouble shows up.
Doors move. Houses settle, wood swells in damp seasons and shrinks in dry ones, and hinges loosen. A door that fit well in autumn may drag in a wet winter or loosen in a dry summer. A lock installed without regard to those changes may work today and bind next season.
The test is straightforward. With the door open, throw the bolt and watch it. It should move smoothly, and fully, with no rubbing. Then close the door and throw the bolt again. If it now drags, the strike is out of line. Look for scratch marks on the strike plate where the bolt has touched. They show which way to adjust.
Small misalignments can be fixed by filing the strike opening, moving the plate, or adjusting the hinges. Larger ones may call for a new strike mortise. The goal is a bolt that slides in and out with no force at all. Our page on night house lockout explains why a lock that needs a shove to latch becomes a failed lock at the worst time.
Hinges and the door itself
A sagging door is the hidden cause of many lock problems. If the top hinge has loosened, the door drops at its latch side, and the bolt no longer lines up. No amount of work on the strike will hold if the door keeps moving.
Check the hinges. Tighten any loose screws. If a screw spins without gripping, the hole is stripped, and a longer screw or a wood filler plug restores the grip. At least one hinge screw on each hinge should be long enough to reach the framing. A door that closes with an even gap on three sides is a door ready for a lock.
Weatherstripping and thresholds affect fit too. A tight seal can push on the latch. A threshold that has risen can scrape the door bottom. These are small points, and a careful installer notes them.
If the door is damaged beyond a simple fix, cracked, warped, or rotting at the edge, say so honestly. A new lock in a failing door is a poor investment. The better choice may be to repair or replace the door first.
Choosing locks for the job, in general terms
Lock types vary, and the right choice depends on the door and the use. We do not name brands here. We describe types.
A standard keyed deadbolt suits most exterior doors. A keypad or electronic deadbolt lets you enter a code, which is useful for shared access or when keys are a nuisance. A smart lock connects to a phone or a hub. Each electronic option adds batteries, settings, and more parts that can fail, so ask about backup keys and what happens when power runs out. A mortise lock sits in a deep pocket cut into the door edge, and is common on older and commercial doors. A rim lock mounts on the surface of the door. A lever handle is easier on hands than a round knob and suits people with limited grip.
Think about who uses the door. Think about the weather it faces. In mountain towns with snow and cold, moisture and freezing affect hardware. In the valley, heat and dust matter. Ask the locksmith what type suits your door and climate.
For doors in shops and offices, see business door hardware, which covers closers, panic hardware and more.
Rekeying to match, and keeping keys together
When you install more than one lock, you can have them all open with the same key. That means the new locks are keyed alike, or the new locks are keyed to match the old ones you are keeping. Decide this before the visit.
Planning matters here. Count the locks. Decide which doors share a key. Our rekey locks page explains how to plan the count and the key sets. Doing both at once saves a second visit.
New locks also give you a clean start on key control. Keys from the old lock no longer work. If you lost track of old keys, that is a quiet benefit of a new lock.
Ask for the number of keys supplied, and ask what it takes to add more. Keep a record of where each key goes. For patio and sliding doors, ask whether a keyed lock, a pin, or a bar suits the door better, since the hardware on those doors differs from a swinging entry door.
What a finished installation should feel like
After the work, test the result as you would use it every day. Lock and unlock with the key from outside. Use the thumb turn from inside. Open and close the door several times with the bolt thrown and retracted. Latch the door gently, and slam it once to confirm it still catches. Lift or press on the handle. Nothing should wobble or rub.
Look at the lock from the side. The faceplate should sit flush. The cover plates should be straight. The screws should be tight. Look at the strike plate. It should be flush and straight, with long screws in place.
Listen. A clean installation is quiet. A grinding, rattling, or scraping sound means something is off, and it is easier to correct while the locksmith is still there.
Finally, ask how to look after the lock. A drop of dry lubricant once a season, a look at the screws twice a year, and a gentle hand on the key keep a lock working for years.
Where we work and how to arrange an installation
The team comes to you. A branded team in uniforms arrives in a branded service van that carries professional tools, key cutting and programming equipment, and common hardware. Installation takes place at your door in Shasta County or Siskiyou County. Our coverage pages list all 17 communities, from Redding and Anderson to Etna and Fort Jones.
If an installation follows a break in or a failed lock at night, our after hours emergency service covers the first steps. Securing the door tonight and finishing the permanent installation in daylight is a common and sound plan.
Send a request through our contact page. A phone line is coming soon, and no number is published yet. Tell us how many doors, what type of door each is, what lock type you prefer, and whether the door sticks or sags. We will plan the visit from there.
Common questions
Can any new lock fit my existing door?
Many fit, since common doors follow standard hole layouts. The locksmith checks the door thickness, the size of the existing holes and the edge recess. If the new lock needs different holes, the door is bored to suit. A cracked or badly drilled door is repaired first.
Why does the strike plate matter so much?
The strike holds the bolt in the frame when someone pushes on the door. Long screws that reach the solid framing give far more strength than short ones in the trim. A flush, aligned strike also lets the bolt move smoothly so the lock works every day.
My new lock is hard to turn. What could be wrong?
Most often the bolt is rubbing in the strike because of misalignment, or the door has sagged on loose hinges. Try the lock with the door open. If it turns smoothly there, adjust the strike or hinges instead of blaming the lock.
Should I choose a keypad or smart lock?
It depends on how the door is used. Electronic locks help when many people need access or keys are inconvenient, but they add batteries and settings that can fail. Ask about backup keys and what happens when power runs out before you decide.
Can new locks work with the same key as my old ones?
Often yes. New locks can be keyed alike with each other or matched to locks you are keeping, depending on the keyway. Plan which doors share a key before the visit so everything can be done in one trip.
What should I check before the locksmith leaves?
Lock and unlock from outside and inside, open and close the door several times with the bolt thrown and retracted, and check for wobble, rubbing or noise. Look at the strike plate and faceplate. Ask how many keys you received and how to care for the lock.