Different Locks Explained

There are many different types of lock, some are insurance standard – some are not. In my blog I want to look at the pros and cons of the different locks. Part one is the Nightlatch lock.

1. The Nightlatch:

The Nightlatch lock is often referred to as a ‘Yale’ type lock. Here, I am going to look at some examples and explain the pros and cons of these locks.

This is the most basic nightlatch. The key or the knob rotate to withdraw the curved latch. The small snib pushed up or down (depending on brand and side of door lock is mounted on) holds the latch either in or out. When the snib is activated the knob and key will not operate.

The part that the key goes into is called a ‘Rim Cylinder’ and can be bought as a separate part. This means if you lose your key, the locking part can be purchased quite cheaply without having to buy the whole lot. They are also easy for the amateur to fit as well, especially if there is already a hole for the rim cylinder to fit into as this passes from the front to the back of the door and into the back of the nightlatch itself.

The downsides to this lock are that as it is cheap, it doesn’t always last very long. If the snib is not activated, a burglar can bypass this lock in seconds. It is possible to accidentally knock the snib as you leave the house and because the latch will retract just a little bit, if you slam your door, you can now be locked out with the key being useless to you. Getting in from this position involves complete destruction of the lock and possible damage to your door. This lock carries no British Standard rating and therefore on its own will invalidate your insurance. Even if the burglar enters through a different opening, having this lock as your only lock on a final exit door will stop the insurance company paying out.

While I see this as a main lock on far too many occasions, I would only use it on internal doors like B&B rooms or if you rent a holiday home and you need to keep some rooms unused, etc.

It can be used on main doors, but there should always be another lock as well, preferably one that is British Standard 3621 with a kite mark.

This is the next level of nightlatch:

This one is a bit more robust than the one before. It’s fitting is slightly more complicated and more tools are required to fit it into place. It operates the same as well. But you can get these in a deadlocking version. That means, if you turn the key an extra turn, the latch is held in place just as the snib would do on the inside. On this example, the snib is black. While this deadlocking action gives slightly more security than the cheaper nightlatch, it does throw up its own problems, because now, if you accidentally rotate the key to the deadlocked position, step inside and slam the door, you will be locked in. The inside lever will not turn enough to free you. You will have to exit from another door or window, and unlock it again from the outside. This, of course is dangerous if you only have one door and fire breaks out.

Again, this lock is not rated to BS3621 and therefore not adequate security on its own.

Finally, the BS3621 Nightlatch:

This one really does the trick. The Rim cylinder is now protected against drilling. The latch comes out further and protects itself against a burglary method called “slipping.” Because the snib is a push button, you cannot accidentally lock yourself in or out as you could with the previous two locks. And because it carries the kitemark, it will satisfy most insurers as a stand alone lock without the need for others. While this is still possible to fit yourself, it can be fiddly and if not done properly, the automatic deadlocking feature will not work. In the image you will notice that there is a key hole on the lever. If you lock the lever in place, a burglar who has entered through another opening wil not be able to open this door and escape with all the stuff he is carrying. However, in the event of a fire, you must be sure where your keys are. There are versions that do not have this locking handle that still conform to BS3621.

Part 2 – coming soon, will be Euro Cylinders & Part 3 Mortice locks.

Should you have any questions regarding the locks above, please get in touch through my contacts page.

Thanks for reading.