Mortice Locks

B&B Locksmiths supplies, fits, repairs and replaces mortice locks for timber front doors, back doors, internal doors and flat entrance doors in homes, rental properties, shops and commercial premises throughout Oxford and Oxfordshire. If your mortice lock is difficult to operate or you are concerned about its condition or security, we can assess the existing lock and advise whether a repair, replacement or upgrade is appropriate.

Mortice locks are commonly fitted to timber doors. The lock case sits in a recess, known as a mortice, which is cut into the edge of the door. Depending on the type of lock, it may incorporate a key-operated deadbolt or a latch and deadbolt operated by a handle and key. The bolt and latch engage with a keep fitted to the door frame.

Types of Mortice Locks

Common types of mortice lock include:

Mortice deadlocks
Mortice sashlocks
Three-lever mortice locks for suitable internal doors
Five-lever mortice locks, including models certified to BS3621

A mortice deadlock uses a key-operated bolt without a latch. A mortice sashlock includes both a latch and a deadbolt, allowing the door to be opened using a handle and securely locked with a key.

Five-Lever Mortice Locks and BS3621

For suitable external timber doors, a mortice lock certified to BS3621 may be appropriate and may be specified under the terms of some home insurance policies. Customers should check the precise lock requirements stated by their insurer.

A five-lever mortice lock is not automatically certified to BS3621. The lock should be checked for the relevant standard and certification rather than relying on the number of levers alone.

BS3621 lock assemblies are operated by a key from both sides of the door. Where the door needs to be unlocked from inside without using a key, a lock certified to BS8621 may be more suitable. BS8621 lock assemblies are key-operated externally and allow keyless operation from inside using a handle or thumbturn.

This distinction can be particularly important where the means of escape must be considered, including on some flat entrance doors. The lock selected should take account of the door, its required fire performance, the means of escape and any requirements specified by the insurer, landlord or managing agent.

When Might a Mortice Lock Need Repair or Replacement?

A mortice lock may need to be repaired or replaced if:

Keys have been lost or stolen
The lock has become stiff, worn or damaged
The bolt no longer operates smoothly
The lock does not align correctly with the frame
The property has changed ownership or occupancy
A security upgrade is required
An insurer specifies a lock meeting a recognised British Standard
There has been a break-in or attempted break-in
The existing locking arrangement does not provide suitable escape from inside where this is required

Correct Mortice Lock Fitting and Alignment

Correct fitting and alignment are important. A mortice lock must align properly with the frame and keep so that the bolt operates smoothly, locks securely and does not place unnecessary strain on the key or internal mechanism.

The lock must also be suitable for the dimensions and construction of the door. Removing too much material or fitting an unsuitable lock case may weaken the door or prevent the lock from operating correctly.

Where a mortice lock is installed in a fire-resisting door or doorset, the lock and associated ironmongery must be suitable for that particular assembly. The installation must not compromise the door’s fire performance, self-closing action or ability to close fully and latch securely.

Mortice Lock Fitting, Replacement and Repairs

B&B Locksmiths can inspect your existing mortice lock and advise whether adjustment, repair, replacement or a security upgrade is appropriate. Where keyless escape from inside is required, we can also advise whether a suitable BS8621 lock should be considered.

If you need mortice lock fitting or repairs, a replacement mortice lock, five-lever mortice lock fitting or a British Standard lock upgrade in Oxford or Oxfordshire, contact B&B Locksmiths for clear, practical advice, professional fitting and reliable local service.