

Change or rekey · Blandford-Blenheim
Deadbolt Installation in Blandford-Blenheim
You bought a keypad deadbolt online and pulled the old one off, only to find the hole in the door is a different size and the bolt latch sits at a backset the new kit does not list.
In plain words
For a main exit door the hardware choice has a safety side as well as a security side. A door people leave a home through should open from the inside without a key, so a single-cylinder deadbolt with an inside thumb-turn is the standard fit rather than a bolt keyed on both faces. Where glass sits close to the lock, the answer is a captive thumb-turn, laminated glass, or a tested security-film system with its specified frame attachment, not a key on the inside. The locksmith explains the trade-offs, fits the lock that keeps a stranger out and the family able to leave, and shows everyone the thumb-turn.
How the visit goesThe bolt on the front door is keyed on both sides. Getting out at night means finding the key in the dark, and with a toddler in the house you have decided the inside should turn by hand. You want it done properly, not just swapped.
Deadbolt Installation
How the visit goes


How the door hangs and closes
Before a new bolt goes in, the door has to close properly on its own, so the locksmith swings it a few times and watches. A door that drops on tired hinges, binds against thick weatherstrip or has to be pulled to latch will put a new deadbolt out of line the moment the season changes. Hinge screws are tested for grip, the gap around the door is read for evenness, and the existing latch is checked against its strike. Small corrections here, such as a longer hinge screw into the framing or a trimmed weatherstrip, are made first so the deadbolt can be set to a door that sits square and stays there.
Cutting a pocket the bolt can fill
The strike is located from the bolt itself rather than from a measurement. The bolt tip is chalked, the door is closed and the bolt is thrown firmly against the jamb to leave a mark at the true centre. The locksmith bores the pocket there with a 25 mm bit to a depth of at least 28 mm, so a 25 mm bolt seats fully and reaches its deadlocked position instead of stopping short and feeling stiff. The pocket is checked with the bolt extended before any plate goes on, because a strike screwed over a shallow hole hides the fault until the first cold morning when the door has moved.
The rest of the door, tidied
A deadbolt installation usually leaves the whole entry better than it found it. Hinge screws that were loose have been replaced with longer ones that bite into the framing, so the door hangs square. Weatherstrip that pinched the door has been trimmed and the latch below the new bolt has been checked against its own strike. The bore edges are clean, any shavings and steel filings have been vacuumed from the sill and the core, and the finish around the new hardware is unmarked. Open and close the door a few times over the next week and let the locksmith know if anything changes as the door settles.
Deadbolt Installation
In the van
25 mm auger bit
Reinforced strike plate
Dry PTFE lubricant
Single-cylinder deadbolt
Boring jig and 54 mm hole saw

Deadbolt Installation
What affects the quote
Rental and building requirements
Matching a building's keyway, providing keys to a landlord or fitting a lock that a condominium corporation specifies can add hardware or bench work, each shown as its own item.
Non-standard bore or backset
Older doors with a small cross bore, an unusual backset or a mortise lock case need adapting or filling before a modern deadbolt fits, and that preparation is quoted before work begins.
Glass near the lock
A captive thumb-turn, laminated glass, security film or a relocated bolt height each carry their own cost, and the choice you make about glass shapes that part of the quote.
What to have ready
- Is the door solid wood, steel-clad or fibreglass, and roughly how thick is it?
- Does anyone in the household have trouble with small knobs or stiff thumb-turns?
- Is there glass in the door or a sidelight beside it within arm's reach of the lock?
Deadbolt Installation: questions
QuestionsCan a deadbolt be added to a door that only has a knob?
Yes, on nearly any wood, steel-clad or fibreglass entry door. The locksmith marks a spot above the knob, clamps a jig to the door and bores a cross hole through the face and a smaller hole through the edge, then cuts a pocket and fits a strike on the frame. The main things checked first are the door's thickness, what is inside it at that height and whether glass sits close by.
Why does the strike plate matter so much?
The strike is the metal plate the bolt throws into, and it is where a kicked door usually fails: short screws bite only into the thin jamb board, which splits. A reinforced strike or strike box fastened with 75 mm screws passes through the jamb into the stud behind, so a blow is met by the framing of the house. On a wood frame, strike screws that reach at least 30 mm into solid wood behind the jamb are what actually holds.
Someone forced my door. Can the new deadbolt go into the same frame?
In most cases, yes. The locksmith examines the jamb for splits and stripped screw holes, glues and pins any cracked section, and fits a full-length jamb reinforcer under the strike so the new long screws bite into sound wood and the stud behind. A new pocket is bored to the correct depth. Where the jamb is beyond repair, replacing that section of frame is discussed before any lock goes on.
Related services

- Lock Replacement & UpgradeThree teenagers, a dog walker, a cleaner and one house key that keeps going missing.
- Vintage Mortise Lock ServiceSomeone painted the door years ago without removing the hardware.
- Smart Lock InstallationYou have just taken possession of the house and the previous owners handed over a keypad deadbolt with a code nobody wrote down and an app account you cannot get into.