Choosing the Right Lock or Latch
Choosing the correct door lock or latch depends on how the door needs to operate, whether security or privacy is required and the type of door furniture being installed.
An internal room door may require only a simple tubular latch, while a bathroom needs a privacy locking function and an entrance door will generally require a more secure lock.
Understanding the main types of locks and latches makes it much easier to choose the correct product.
Door Latches
A door latch holds a door closed but does not normally provide a key-operated locking function.
Tubular mortice latches are one of the most popular choices for internal timber doors and can be used with most lever handles and suitable mortice door knobs.
Latches are available in different lengths, with 2½", 3" and 4" tubular latches commonly selected depending on the required backset and type of door furniture.
Longer latches can be particularly useful with door knobs because they position the knob further away from the door frame.
Mortice Locks
A mortice lock is installed into a recess cut into the edge of the door, leaving most of the locking mechanism concealed.
There are several types of mortice lock.
A mortice sash lock combines a latch and deadbolt, allowing the door to operate normally with a handle while also providing a key-operated locking function.
A mortice deadlock provides a locking bolt without a spring latch and is commonly used where a separate latch is not required or as an additional locking point.
Bathroom mortice locks combine a standard latch with a privacy bolt operated using a thumbturn.
Rim Locks
A rim lock is fitted onto the surface of the door rather than being concealed within it.
Traditional rim locks are particularly popular in period properties, cottages and restoration projects, where the lock itself can form an attractive part of the architectural ironmongery.
They are commonly paired with traditional rim knobs and are available in a range of decorative finishes.
Cylinder & Euro Profile Locks
Many modern locking systems use a separate Euro profile cylinder to operate the lock mechanism.
Euro cylinders are available in different lengths and configurations, including key-to-key and key-and-thumbturn options.
Keyed-alike cylinders can also allow several compatible locks to be operated using the same key, which can be particularly useful in residential and commercial buildings with multiple doors.
Always check the cylinder dimensions carefully before ordering, as the correct length will depend on the thickness of the door and fitted ironmongery.
Security Locks
Where security is a priority, the performance and certification of the individual lock should be considered rather than selecting a lock based on appearance alone.
Different entrance doors may require mortice locks, cylinder-operated systems, multipoint locking mechanisms or additional deadlocks depending on the construction of the door and required level of security.
If an insurance policy, specification or building requirement refers to a particular security standard, check that the selected lock is tested and certified accordingly.
Frequently Asked Questions
What is the difference between a lock and a latch?
A latch holds a door closed and is normally operated using a door handle or knob.
A lock provides an additional securing function, generally using a key, cylinder, thumbturn or other locking mechanism.
Some products, such as mortice sash locks, contain both a latch and a lock within the same case.
What type of latch do I need for an internal door?
A tubular mortice latch is commonly used for internal doors fitted with lever handles or mortice door knobs.
The correct length will depend on the required backset and the type of door furniture being used.
What is the difference between a sash lock and a deadlock?
A sash lock contains both a spring latch and a locking deadbolt.
A deadlock contains only the locking bolt, without the spring latch used to hold the door closed during normal operation.
What lock should I use on a bathroom door?
A bathroom mortice lock is normally the most suitable option. It combines a latch operated by the door handle with a privacy bolt operated using a thumbturn.
What is a rim lock?
A rim lock is mounted onto the face of a door rather than being recessed into the door edge.
Rim locks are particularly popular for traditional interiors and period properties, where they are often paired with decorative rim door knobs.
What is a Euro cylinder?
A Euro cylinder is a removable key-operated cylinder used with a compatible lock case.
Different cylinder configurations allow options such as key operation from both sides or a key externally with a thumbturn internally.
Can I replace an existing lock with a different type?
Sometimes, but it will depend on the existing door preparation and dimensions.
When replacing a lock, important measurements can include the case size, backset, centres, faceplate dimensions, cylinder length and position of the existing cut-outs.
Where possible, replacing an existing lock with a compatible size and configuration will normally make installation considerably easier.
Need Help Choosing Locks & Latches?
With different lock cases, latch lengths, cylinder sizes and security options available, selecting the correct door hardware can sometimes be confusing.
Roundtower Hardware supplies a comprehensive range of door locks, door latches, mortice locks, rim locks, cylinder locks, security locks and architectural ironmongery throughout Ireland.
Browse the relevant category online, or contact our team with your door details and measurements and we can help you identify the correct lock or latch for your project.
