How To Hang & Fit An Internal Door: A Step-By-Step Guide 

Hanging and fitting an internal door correctly is essential in ensuring smooth operation, a snug fit and long-term durability. Whether you're replacing an old interior door or installing a new one from scratch, knowing how to hang a door properly will make all the difference to the aesthetics and functionality of your home.

Although it can be a challenging task, with the right tools, careful measurements and a methodical approach, an experienced DIYer could achieve a professional finish. The key is preparation, accuracy and patience. However, if you have any doubts or are uncertain of your abilities, it’s always best to use the services of a professional carpenter - one wrong move and you could be looking at an expensive replacement before your door is even in place.

In this guide, Door Giant will take you through the process of hanging an internal door step-by-step, from choosing the right door to making precise adjustments for a perfect fit. Whether you’re working with a hollow core, solid wood or moulded panel door, the principles remain the same.

1. Gather The Right Tools & Materials

Before you begin, make sure you have the following tools and materials:

• A new internal door
• Hinges (check with your door manufacturer, but most doors usually require three hinges)
• Screws (suitable for your hinges)
• Tape measure
• Pencil
• Chisel and mallet
• Drill and screwdriver
• Plane (for trimming)
• Spirit level
• Handsaw or circular saw (if trimming is needed)
• Sandpaper
• Door latch and handles (if replacing old hardware)

Having everything ready will make the process smoother and help you avoid unnecessary delays.

2. Measure & Prepare The Door

Internal doors typically come in standard sizes, but some adjustments may be necessary if your frame isn’t perfectly square.

• Measure the height and width of the door frame at multiple points to check for inconsistencies.
• If the door is too large, mark where it needs trimming. Always refer the trimming allowance guidelines from your door manufacturer - taking too much off could expose the core and compromise the door’s integrity.
• Use a plane or saw to carefully reduce its size. Always remove small amounts at a time to avoid over-trimming.
• Sand down any rough edges to ensure a smooth finish.

Once you’ve sized the door correctly, position it within the frame to double-check the fit before proceeding.

3. Mark & Cut The Hinge Recesses

Correctly positioning the hinges is crucial for smooth door operation. Follow these steps:

• Lay the door flat and position the hinges in line with those on the existing frame (typically 150mm from the top and 225mm from the bottom).
• Use a pencil to outline the hinge plates.
• With a chisel and mallet, carefully create shallow recesses (known as hinge mortices) so the hinge plates sit flush with the door surface.
• Screw the hinges into place securely, ensuring they align properly.

Repeat the same process on the door frame, making sure the hinges match perfectly.

At this point, it’s also a good idea to measure and drill any holes required for fitting your handles and latch. Mark the correct height for the handle (usually 900mm from the floor) and drill the necessary holes.

4. Hang The Door & Check Alignment

Now it’s time to attach the door to the frame:

• Align the hinges on the door with the hinge recesses in the frame.
• Secure the hinges using screws, ensuring they are flush and tight.
• Slowly open and close the door to check for smooth operation.
• Use a spirit level to ensure the door hangs straight and isn’t sticking or misaligned.

If necessary, make slight adjustments to the hinge positions to improve the fit.

5. Fit The Door Handles & Latch

With the door securely in place, the final step is to install the door handles and latch.

• Fit the latch mechanism into the door edge and secure it with screws.
• Attach the handles on both sides, ensuring they operate smoothly.
• Finally, fit the strike plate to the frame and test the latch to ensure the door closes securely.

Hanging an internal door might seem like a daunting task, but with careful planning, patience and the right tools, it can be a rewarding DIY project. By following these steps you can achieve a professional finish that enhances both the functionality and appearance of your space.

Taking your time with each stage will ensure the door operates smoothly and lasts for years to come.