

Change or rekey · Newmarket
Lock Replacement & Upgrade
The lever on the side door droops toward the floor and rattles in your hand.
In plain words
A replacement lock has to fit holes that already exist, and that is where the visit begins. The locksmith measures the backset, the distance from the door edge to the centre of the bore, which on most doors is 60 or 70 millimetres, checks the cross-bore diameter and edge-bore size, notes door thickness and handing, and looks at the strike cut-out. Most residential hardware is made to these standard preparations, so the new lock usually drops into place with no new drilling. Where a mortise lock or a thick door departs from the norm, filler plates, extension kits or a careful new bore bring the door up to standard.
How the visit goesThe century home's original mortise lock takes a key the size of a spoon, sticks in humid weather and has worn its strike to a groove. You want a lock that works every day without giving up the old door.
Lock Replacement & Upgrade
How the visit goes


The key plan for the whole house
A lock is only half of a system; the other half is who holds which key. The locksmith asks how many exterior doors there are, which ones should open with the same key, whether a garage man-door or a shed should join them, and who in the household needs a key of their own. If keys have been lent out over the years, the plan can retire all of them at once. Where copying keys without permission is a worry, a restricted keyway can be offered. Settling this before the hardware is chosen means the new locks arrive ready to be pinned alike rather than fixed up afterwards.
Setting and reinforcing the strike
The strike side is where a replacement earns most of its value. With the door closed, the bolt is thrown and its mark checked against the pocket so the strike can be positioned to accept the full throw without rubbing. A shallow pocket is deepened until the bolt seats to its stop. Then a reinforced strike or a strike box is fitted using 75 millimetre screws that pass through the jamb and bite into the framing behind it, which is what stops a jamb splitting under a kick. Where an old forced entry has cracked the wood, it is glued and dowelled or a repair plate is fitted first.
A smart lock with its backup arranged
A keypad or smart deadbolt leaves the visit with codes set for each person, auto-lock and alerts configured, and any phone pairing confirmed while the locksmith is there to check it. You are shown the low-battery signal so you recognise it, and the type of battery the maker calls for. The mechanical override key is the piece to look after: keep it on a keyring or with a neighbour rather than inside the home it opens. A second person's code is set up before the locksmith leaves, so a flat phone or a forgotten code is never a reason to stand on the porch.
Lock Replacement & Upgrade
In the van
Key blanks and key cutter
Filler plates and thick-door extension kits
Adjustable latch or bolt
Reinforced strike plate and strike box
Handleset with matching deadbolt

Lock Replacement & Upgrade
What affects the quote
Number of doors
One back door is a small visit; the front, back, side, garage man-door and patio slider together are a longer one, though several doors done at once share the travel and setup.
Patio and French door hardware
Sliding door mortise locks, foot bolts and flush bolts for an inactive French door leaf are specialty items sized to the door, and they are quoted as their own line beside the entrance work.
Condition of the old hardware
Hardware that comes off cleanly is one thing; painted-over trim, seized or stripped screws and a cylinder that has to be drilled out add time before the new lock can go on.
What to have ready
- How many keys does the household need, and should copying be restricted?
- Has the door been forced or damaged, or does it need a push to lock?
- Is the problem wear, damage, looks, a change of function or too many keys?
Lock Replacement & Upgrade: questions
QuestionsWhat information helps before the visit?
Photographs of each lock from outside and inside, plus one of the door edge showing the latch plate and one of the strike on the frame, tell the locksmith most of what they need. Add the door thickness if you can measure it, whether the door is wood, steel or fibreglass, the finish you want to match, how many doors are involved and whether you want them all on one key.
Can I stop people copying my house key?
A restricted keyway helps with that. The key blanks are controlled by the manufacturer and its authorised locksmiths, so a copy generally requires the card, record or authorisation the program uses, cutting down on copies made at an ordinary kiosk. It suits homes where keys are lent to cleaners, contractors or tenants. The cylinders are fitted in the normal way, and you keep the key card safe because it is what future copies depend on.
My old house has a mortise lock. Can it take modern hardware?
Often the original case can be kept and given a new cylinder and strike, which keeps the period look and the old door intact. Where the case is beyond service, a filler or conversion plate covers the mortise pocket and lets a cylindrical deadbolt or knob set be fitted without cutting into the door's stile. The locksmith looks at the door before recommending either path, since old doors vary a great deal.
Related services

- Deadbolt InstallationYou 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.
- Vintage Mortise Lock ServiceThe interior bedroom doors on the second floor have the original mortise latches, and none of them close any more.
- Smart Lock InstallationThere are four copies of the front-door key floating around: one with the cleaner, one with a neighbour, one on a hook at your parents' place, and one you honestly cannot account for.