How to Hang an Internal Door

If you’ve decided it’s time to replace an old or outdated internal door, you may be able to save some time and money by fitting it yourself. Hanging an interior door needn’t be as daunting as you might think. With the right tools and our handy step-by-step guide, you can get the job done right.

In this article, find out:

What tools do you need?

A successful door installation starts with ensuring you have the right tools. Check you’ve got everything you need before you get started. 

How to measure internal doors

There are different steps you’ll need to take depending on if you’re measuring an empty door frame or you’re replacing an existing door. Grab your tape measure, pencil and paper and let’s get started. Here is a short video on how to measure a door. 

Measuring an existing door within the frame

If you have a well-fitted door that you want to replace, you can measure the existing door in a few easy steps. 

1. Measure the width of the door in three places – at the top, middle and bottom. Record the largest of the three measurements. If the existing door has glass panels, measure on the flat, non-glazed surface.

2. Measure the height of the door in two places and again record the largest measurement.

3. Finally, measure and record the depth of the door. The depth of the door is important because it determines the size of the hinges you need to purchase.

Measuring within an empty frame

1. Measure the width of the door space in three places at the top, middle and bottom and record the largest of the three measurements.

2. Measure the height in two places and record the largest measurement. Consider whether there is a threshold strip in place.

3. Measure the depth from the edge of the frame to the door stop. 

Choosing the right door for you 

Once you’ve got your measurements, it’s time to pick your doors. 

Explore our range of solid core internal doors. 

Bear in mind that some door frames may not be a standard size, so you may need to trim your new door to fit. Different doors allow different amounts of trimming, so if you can't buy the exact size, check the amount you can trim to achieve the perfect fit. Find out how to do this further down this article. 

If you need a hand deciding which door best suits your home, check out our interior door buying guide. You’ll learn about the different types of doors, materials and finishes, 2023 door trends and colour ideas. 

Preparing the door

Before you hang your door, there are a few steps you can take to get the right fit and finish. 

● Lay your door flat, unwrapped in your home for a minimum of 24 hours before fitting the door, to allow for any expansion or contraction (unless instructions for your particular door state otherwise) 

● Hold the new door in the frame to see if it needs any adjustments. Alternatively, if the old door is available (and was well fitted) you may place the old door on top of the new door and use it as a template to guide where the new door may need adjusting/trimming. A well-fitted door should have 2-4mm gaps on either side and at the top. If you need to trim your door, check the manufacturer’s instructions for the maximum amount that can be removed from the door's bottom and sides. We don’t recommend trimming the top of the door because this is where the door ID is located. 

● Use a pencil to mark up how much needs trimming. For the sides, measure the amount and divide by two so you make equal reductions on both sides, so you don’t end up with one half of the door wider than the other. 

● Plane the door as required and sand it for a smooth finish.  Alternatively, use a panel saw or circular saw to remove larger amounts. Ensure that you cut in a completely straight line.

● If you’re planning on painting your doors, read how to paint interior doors like a pro for a handy step-by-step guide.

How to hang a door

If you’re a more experienced DIY-er, you may feel confident and capable of fitting the door on your own. However, doors can be heavy, so an extra pair of hands can come in handy. If you can, draft in a partner/family member/friend for extra support. 

Ok. Doors ready? Tools ready? You’re ready to fit your door. 

Step 1: Remove the old door 

Support the door – or ask your spare pair of hands to do this – while you unscrew the hinges. Start with the bottom hinges first and work your way up. Clean off any old paint on the hinges/screws if you plan on using them for the new doors. 

Step 2: Fitting the hinges 

Before marking or chiselling your door, make sure you fit your door the correct way around, as this can differ across door types. Hollow core doors have a 'lock block' inside on one side. This is a solid piece of timber to secure your latch/lock handles to. It is usually marked on the top edge of the door indicating which side. You can also tap the door to double-check – it will sound hollow on the hinge side and solid on the lock block/handle side. 

If you’re replacing an internal door (rather than starting with an empty door frame), try using the same sized hinges and hinge positions as the original door if you can. It will make things a lot easier! Otherwise, you’ll need to make new hinge positions.

● Hold the door in position and use small wedges underneath to create a consistent 3mm gap between the door and the frame on all sides.

● Mark the position where the existing hinges should rest on the door. Hinges should ideally sit between 150mm to 200mm from the top and bottom edge of the door, with the third hinge (if needed) in the centre of the frame. 

● Lay the door flat and line up the hinges with the marks you made. Carefully draw around them to mark their outline on the door.

● Measure the thickness of the hinge plate and mark a line of the same thickness on the edge of the door.

● Chisel out the area you’ve marked to create space for the hinges. 

● Place the hinges on the hinge side of the door, ensuring they are level and spaced evenly.

● Drill pilot holes where the screws will go and screw the hinge to the door. Repeat for the other hinges. Then screw the hinges to the door.  

Step 3: Hanging the door

Put the door back in the door frame so it’s open to 90 degrees, supported by the door wedges. Tighten in two screws – one in the fixing hole closest to the floor and another closest to the ceiling. Check that the door opens and closes smoothly. 

If it does catch, mark the area that needs planing or sanding and trim it down. 

When you’re happy the door opens and closes cleanly, secure the door by screwing in the remaining hinge screws.  

Step 4: Carry out any finishing touches

Once your doors are in place, you can start making cut-outs for handles, painting, staining, oiling, or adding hooks.

Finding a joiner

We hope our step-by-step guide gives you an understanding of how to fit your doors however, it can be a daunting task – especially if you uncover crooked door frames, or if you’d like to swap around the way the door opens. Hiring a joiner is always the best option – with their experience and expertise, they'll be able to install the door quickly and accurately.

Places to find joiners

● Local recommendations – Check out local Facebook groups and Next Door for frequently recommended joiners or create a new post. Stenhouse Doors & Joinery is one of the many local joiners you can find on Facebook.

● Family, friends and neighbours – Getting a recommendation for a joiner from someone you know and trust can give you extra peace of mind; you may already have seen some of their work. 

● Online – Many websites allow you to post details of your job and receive quotes from local tradespeople. Their profiles usually display a customer rating and their work, so you can get a good idea if they’re the right fit for you. Check out mybuilder.com , checkatrade.com , myjobquote.co.uk , and trustatrader.com .