Need help choosing the right lock?
Choosing the right lock for you can be confusing. There are so many options out there it’s not only first time buyers that can succumb to the sheer amount of choice on the market place. Luckily we are here to guide you through the jargon so you get exactly what you need first time.
So, first on the agenda, are you replacing an existing lock?
If so then things are pretty straight forward, what I list below is a basic checklist to get you pointed you in the right direction. Let’s assume for the purpose of this guide that you are trying to replace a lock like-for-like. This simplifies things because we have a datum, or point of reference to begin with.
1.) Is it an external or internal door?
This is the very first step, identify the position of the door in the house, this will give us the first requirements to help identify the door. This follows very closely to the next question, between these two first points we are going to rapidly narrow down the fields.
2.) What type of key does the existing lock have?
This helps us further narrow down what type of lock you need. Basically there are 2 different types of keys used for both internal and external door locks. The two different types are shown below, to the left is a lever lock key, the one to the right is a key for use with a cylinder lock, probably the most common these days, the difference in styles is quite clear.
3.) When looking at the edge of the open door, does the lock for-end plate run up the whole length of the door or only a few inches?
If the lock appears to run up the whole length of the door then it is most likely what is known as a multipoint lock, these can be fitted to either wooden or UPVC doors and will have multiple pieces which extend from the edge of the door such as hooks, rollers and sometimes multiple deadbolts. A multipoint lock is a very specific type of lock case and must be matched as closely as possible to the original, count how many hooks or rollers it has and make a note of the positions. As long as the old version matches up with the new one don’t worry about its length, these types of locks are designed to be cut down at the top and bottom so don’t be surprised if the lock you receive is too long for the door!
4.) Does the lock have a set of handles or does it just open with a key?
This determines whether you have a sash lock or a dead lock. A sash will have a deadbolt and a latch, accompanied by handles. A deadlock will not have any handles and are usually fitted to the top, bottom or both ends of a wooden door. For more information on the differences between a sash and a dead lock, check out our previous guide here.
5.) What size is your existing lock?
So if you’ve got this far then we have successfully narrowed your choice of lock to just a few options left.
We just need the last few measurements to get an exact match. The easiest and most error-free way for you to do this is to actually remove the old lock from the door, it’s very easy to do and will give you good practice for when your replacement arrives.
Simply remove any door handles and cylinders from the door then remove the for-end plate and the two screws beneath this holding the lock case into the door. It should just pull out free from the door at this point. Make a note of the dimensions specified in the diagram below:
The above image gives 6 different measurements of a standard sash or dead lock case, to help you filter through the jargon, the specific names for these parts are given below.
A= Case Depth (The distance the lock case goes into the door)
B= Backset (The distance from the edge of the door to the centre of the spindle or keyhole)
C= Case Height
D= PZ (Distance between the centre of the spindle and the centre of the keyhole)
E= Forend Length
F= Forend Width