How to Fit a Mortice Lock Like a Pro

Enhancing the security of your doors is a crucial step in fortifying your home against intruders. One reliable solution that always stands the test of time is the mortice lock and in this guide, you’ll learn the process of installing one like a pro.

From the essential tools you’ll need to expert tips on how to fit a mortice lock, you’re about to empower your doors with a robust security upgrade, so let’s dive in.

Mortice lock specifics

Mortice locks are designed to fit into a specifically cut pocket (mortice) in the door. Contrary to a common belief, they work well with wooden doors when installed accurately. Precision is crucial during fitting, and with the right tools and know-how, it won’t compromise the door’s integrity. As a matter of fact, mortice locks are versatile and work with both wood and metal doors.

Mortice locks are broadly categorised into two types:

If you are interested in learning more about door locks, head over to our post on the matter. There you’ll find what types of door locks exist, how do they work and look.

If you, however, want to learn more about mortice locks specifically, then we have a full guide dedicated to mortice locks, where all features, types and purposes are reviewed in detail.

How to properly fit a new mortice lock

Now that you know what a mortice lock is, you first need to gather all the necessary tools for installation.

What tools you will need:

The installation process is consistent for both sash locks and deadlocks. However, it’s crucial to note that different mortice locks are specifically designed for varying door thicknesses. Therefore, you need to select a lock that suits your door to avoid potential damage during the mortice-cutting process.

Sashlocks are suitable for doors of average thickness. It typically accommodates a range of door thicknesses, making it versatile for standard residential doors. Deadlocks, on the other hand, are ideal for doors with varying thicknesses, including both standard and thicker doors. They are often selected for applications where increased security is a priority.

Also consider the door material before starting, as installation procedures vary based on the material, requiring potential adjustments. Be aware of specific installation requirements for different mortice locks and consult the manufacturer’s instructions for guidance if necessary.

Mortice lock installation process:

1. Ensure stability during installation by placing a wedge under the door;
2. Position the mortice lock body on the door, marking the top and bottom edges, keyhole, and handle hole locations with a pencil;
3. Drill holes into the door according to the marked areas. For the keyhole, begin with the top hole and use a thin pad saw for precision;
4. Choose a spade bit slightly wider than the lock body to drill the cavity, ensuring a proper fit;
5. Align the drill bit with the lock body to mark the correct depth on the shaft using masking tape;
6. Drill several holes along the marked line, one below the other, and chisel out the wood between the holes, smoothing rough edges;
7. Attach the faceplate to the mortice lock, placing them into the cavity. Additional chiselling may be necessary for a snug fit;
8. Mark the faceplate edges with a Stanley knife, and carefully chisel out the wood along the markings to ensure a secure fit;
9. Insert the lock body into the mortice and secure it with screws;
10. Install the handle and key plates using the provided screws and bolts according to the manufacturer’s instructions;
11. Always follow the specific guidelines provided by the lock manufacturer to achieve the required level of precision during the installation process.

How to replace an existing mortice lock

Before purchasing a new lock, accurately measure the following distances on your existing door lock. This is how to measure a mortice lock:

1. Measure the distance from the front edge of the door to the centre of the keyhole;
2. The space between the keyhole and the door handle spindle hole;
3. The height of the faceplate.

For a smoother replacement process, it’s advisable to have your old lock with you when shopping for a new one.

Here’s a step-by-step guide on how to remove the old lock:

1. Open the door;
2. Unscrew the screws securing the faceplate;
3. Remove the door handles and the spindle that connects them;
4. While holding the bolt with pliers, pull out the lock body.

Now, place mortise lock replacement:

1. Insert the new lock body into the existing mortice. Some adjustments to the cavity with a chisel and hammer may be necessary for a proper fit;
2. Remove the old keep from the door frame and replace it with the new one. Again, adjustments to the space with a chisel and hammer may be needed to ensure a snug fit for the new keep.

How long does it take to fit a mortice lock?

How long to fit a mortice lock can vary based on several factors. On average, it may take anywhere from 30 minutes to an hour to complete the installation. However, the actual duration can be influenced by the following factors:

Average cost to fit a mortice lock

To fit a mortice lock in the UK, the average cost varies based on factors such as the type of lock and the locksmith’s rates. Here’s a quick breakdown of what you can expect, but mind you, these prices are mere estimates and a professional might give you a different quote.

New lock fitting price

Lock replacement price:

For more detailed information and a comprehensive locksmith price guide in the UK, you can refer to Fantastic Services’ Locksmith Prices UK Guide.