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Lock Installation in Wandsworth
Lock Installation throughout Wandsworth, day or night, 365 days a year — average response 15 minutes. Free call-out with every job — fixed price agreed before any work starts.
Other locksmith services in Wandsworth need lock changes, repairs, upgrades or commercial help instead?
All services in Wandsworth →Common failure modes on Victorian terrace locks trace back to the door rather than the hardware: a bolt that jams partway through its throw is almost always a keep alignment problem rather than a faulty case. We test under the actual closing pressure of the door — not on the open door — because frame pressure is part of the operating environment the lock lives in every day.
On arrival
Measurement checklist: what we record on arrival
Four measurements are taken before any hardware comes off the van on a Wandsworth installation. A wrong-part revisit costs more than two minutes of careful measuring — we never skip this step.
| Measurement | Why it matters | Typical range |
|---|---|---|
| Stile width | Sets which transom rail clearance case will physically fit without weakening the door at the lock rail. A transom rail fitted above the main door panel reduces the available upper stile zone — confirm there is at least 80 mm of solid stile timber above the nightlatch before fitting a supplementary top bolt. | 44 mm minimum for a full BS3621 mortice; narrower stiles may require a slimline case or a euro-cylinder alternative |
| Frame recess depth | Victorian period door height geometry: mortice centre height is measured from finished floor level and recorded. Top bolt position is confirmed against the available solid stile zone above the nightlatch — minimum 80 mm of solid timber required for the top bolt fixing screws. | 13–20 mm on most residential timber; composite and UPVC frames can run shallower |
| Door thickness | Controls the cylinder length from face to face. A cylinder sitting proud of the outer face — even by 3 mm — creates a snap-attack leverage point that defeats anti-snap ratings. | 44 mm (standard timber), 54 mm (solid composite), 70 mm (hardwood or fire-rated) |
| Cut-out position | The distance from the door edge to the centre of the existing cut-out sets the backset. Extending an existing cut-out adds time and cost; fitting into the existing position is preferred wherever the hardware allows it. | 45 mm backset (most residential); 60–70 mm on commercial and period doors |
All four measurements are recorded on the job card and referenced in the installation certificate. If the measurements reveal a door that cannot accept the specified hardware without prep work, that is flagged and quoted before any tools come out.
Before quoting
Six door conditions that change the Wandsworth quote
Period ironmongery on Victorian terrace doors — original escutcheons, knobs, and knockers — can add to installation time if the replacement case must be positioned around retained decorative hardware. We identify retained ironmongery on arrival and factor its position into the case location before quoting the final price, so the figure reflects the actual fitting conditions on that door. From £59 for a standard installation on a door in good condition.
- 01 Narrow stile
Terraced flat doors in Lambeth and Wandsworth that carry an AV intercom strike unit on the stile may have the strike body already occupying part of the available depth. The strike unit depth and the BS3621 case body depth are checked against the stile measurement together; where they compete for the same zone the strike is relocated to the frame jamb rather than the door stile to free the full stile width for the mortice case.
- 02 Composite vs timber construction
Composite and UPVC doors use a different cylinder system from timber — euro profile with a multipoint gearbox rather than a mortice. Mortice centre height from floor level is recorded on the job sheet for all installations — this measurement is used to locate the keep on the frame without re-hanging the door. Confirming construction type before ordering avoids a wrong-part visit.
- 03 Existing cut-out dimensions
On leasehold flat doors in Tower Hamlets and Lewisham the managing agent may require the original cut-out dimensions to be logged as part of the building maintenance record before any work begins. Both the pocket depth and the forend recess width are photographed and recorded on the job sheet, a copy of which is provided to the leaseholder for forwarding to the building manager on completion.
- 04 Nightlatch position
HMO front doors in Hackney converted from original single-family use may have a nightlatch at a height set for the original occupier, which is now inconvenient for multiple users. As part of a full lock replacement the backplate height is re-set to the current recommended position of 990 mm to 1050 mm from floor level, and the old strike pocket is plugged in the frame before the new rim keep is fixed.
- 05 Frame condition
We measure the transom rail clearance above the nightlatch the frame for squareness, settlement, and rebate wear before committing hardware to final position. A frame that is out of square or has a worn rebate needs addressing first — fitting a mortice into a moving frame produces a bolt that binds within months.
- 06 Letterbox clearance
Conservation area letterbox plates on London terrace doors in Camden and Islington must match the period character of the door — a modern slot plate is unlikely to satisfy the local authority condition. The existing plate aperture and fixing centres are measured before a replacement is ordered, and a cast-brass period-style plate with matching proportions is specified to satisfy any conservation condition attached to listed building consent.
Specification
Hardware compatibility: will this door accept BS3621?
Three questions answer most hardware compatibility conversations on a Wandsworth installation. We work through each on arrival and confirm the spec before any cutting or drilling starts.
- 01
Can this door accept BS3621?
A BS3621 5-lever mortice requires a minimum stile width (44 mm), a frame rebate to accept the forend, and sufficient door thickness at the lock rail. We check all three before specifying — a door that cannot take a BS3621 case without structural compromise will be quoted with a compliant alternative using a transom rail clearance or upper stile zone instead.
Upper stile zone must be in solid timber, not in the glazing bar area or a thin moulding — check the inner door profile before fitting a top bolt in the upper zone.
- 02
Cylinder size: 35/35 vs bespoke
Standard residential doors run 35/35 or 35/45 euro cylinders; composite and commercial doors often need bespoke lengths. We confirm the upper stile zone for a top bolt the cylinder run on site — face to face across the door leaf at the lock rail — and confirm the top-bolt supplementary specification before fitting. An oversized cylinder leaves the anti-snap collar exposed.
Anti-snap cylinders must be sized with the break-point inside the door face. A cylinder that is even 3 mm too long on the outside is vulnerable to a snap attack regardless of its anti-snap rating.
- 03
Nightlatch: rim vs mortice
Rim nightlatches surface-mount on the door face and require backplate clearance from the door edge and from any adjacent furniture. Mortice nightlatches fit into the door thickness and suit doors where the face is already occupied by a letterbox or knocker. The choice depends on the stile geometry confirmed at measurement, not a preference.
On insurance-graded installs both the primary lock and the nightlatch are noted on the compliance certificate. If the policy specifically names a rim nightlatch at a given standard, we confirm that against the door construction before the certificate is issued.
Completion
Handover and testing
The installation is not complete until every lock has passed a full function test on a closed door. On Wandsworth jobs we sign off three checks before handing back keys.
- Cycle test
London terrace doors in Lewisham and Greenwich that face north can accumulate damp in the bottom rail during wet periods, causing the door to drop slightly on its hinges. The cycle test includes a check that the bolt height at the keep mouth matches the as-fitted measurement; any drop greater than 2 mm indicates a hinge problem that is rectified before the lock installation is signed off.
- Key issue
Keys are counted against the job card in front of the keyholder. Each key is labelled with the door reference it was cut for. No key leaves site unaccounted — if the agreed number is not present at handover, the job card flags the discrepancy before the engineer leaves.
- Written summary and certificate
For leaseholder-owned flats in Brent and Waltham Forest the handover summary confirms that consent from the freeholder or managing agent was obtained before the lock change, where that consent is required by the lease. The consent reference or approval date is recorded on the summary so the leaseholder has an auditable trail in case the managing agent queries the installation at a future date.
Questions
Lock installation FAQ: Wandsworth
On Victorian and Edwardian doors the critical measurement is the existing mortice cut-out — it sets the ceiling on which 5-lever models will drop in without additional prep, and therefore what the job actually costs.
- Do I need to measure my door before calling?
- Our engineer does all the measuring. For Barnet and Enfield Victorian terrace doors with a period door knocker set centrally, the knocker back-iron can sit very close to the stile edge and restrict calliper access. The engineer uses a slim-profile depth probe to measure the pocket depth adjacent to the knocker back-iron without removing it, so the door is not disturbed and the measurement is still accurate.
- Will the new lock look different from the original?
- On like-for-like replacements — same case position, same forend size — the external appearance changes only in terms of the new cylinder rose or escutcheon. On period doors where the original furniture is being retained, the escutcheon fit is checked for compatibility before the hardware is sourced. Where the new spec requires a different door face profile (e.g. switching from a mortice keyhole to a euro cylinder profile), we flag that on the booking call before the job date.
- How long does a Wandsworth lock installation take?
- A standard like-for-like cylinder replacement on a composite or UPVC door takes around 30–45 minutes including the full test cycle. A new BS3621 mortice installation on a timber door — where the existing cut-out is the right size — takes 60–90 minutes. If the door needs prep before the hardware fits (rebate adjustment, aperture extension, hinge correction) we agree the additional time and cost before starting. We do not proceed past the assessment stage without a confirmed price.
- What if the door needs repair work before the lock can be fitted?
- Lime mortar keep-plate anchors in Islington and Camden conservation area frames can be friable if the mortar has not been repointed in decades. Where the existing keep plate is loose, the frame behind it is raked out and repacked with fresh lime mortar compatible with the original mix; the new keep is then fitted after a short set period and tested with a full bolt throw before the job sheet is completed.
Lock Installation in Wandsworth — FAQ
Common questions about lock installation in Wandsworth.
Can you install a lock on a brand-new door?
On Victorian and Edwardian doors the critical measurement is the existing mortice cut-out — it sets the ceiling on which 5-lever models will drop in without additional prep, and therefore what the job actually costs. Yes — this is one of our most common installation jobs in Wandsworth. Carpenters and joiners often hang the door and leave lock fitting to specialists. We measure the rebate, chisel for a BS3621 mortice case, fit the strike plate, and test through a full key cycle. Finished work looks factory-fit.
Do I need BS3621 on a new installation?
For external doors on Wandsworth homes with standard insurance — yes, almost certainly. BS3621 is the minimum most UK home insurers specify on final-exit wooden doors. We fit BS3621 as standard and issue written paperwork confirming the standard for your insurance file.
Can you keyed-alike multiple new locks?
Yes — if you want one key to open your front and rear doors, we supply keyed-alike cylinders on the most common profiles. Arrange at the survey stage so we bring matching parts. This works cleanly on UPVC euro cylinders and on certain mortice profiles.
We've just moved into a new-build in Wandsworth — do the locks already meet insurance standards?
Not always. Many Wandsworth new-builds come with entry-level euro cylinders on UPVC or composite doors that lack the TS007 3-star anti-snap rating, and sometimes a mortice case that predates BS3621 on the side door. We survey the whole property, identify any hardware gaps, and upgrade to compliant standards on the same visit — with a compliance pack for your insurer.
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