How to Install Internal French Doors

Correct installation, with some basic preparation and maintenance, will go a long way to ensuring the longevity of your internal French doors. In this article, we’ll look at how you install internal French doors, and answer some common questions that come up about the process. We’ll explore the different ways you can configure your doors to meet, as well as how difficult the job is likely to be and how long it will take.

How to Install Internal French Doors

In many ways, the process for installing French doors is the same as installing a single-leaf internal door. You just need to do the steps twice, one on each door. Of course, it is slightly more difficult as well, with twice as many steps that you need to get exactly right. The main difference is that instead of setting your latch plate into the door frame, you set it into the slave door instead. Below are the tools and steps you need to get your internal French doors hung. Tools you will need:

• Mallet
• 25mm Chisel
• Pry bar (if removing old door frame)
• Drill
• Hinges
• Screwdriver
• Screws
• Pencil
• Spirit level

Step-by-Step Guide

1. Before you hang internal doors, you will need to make sure that the opening is as square as possible using a spirit level. This is because any slight difference will impact both doors and stop them from working properly.
2. If you are replacing the door frame, pry the old frame out of the opening, then install the new one. Use shims to make sure it is level and hold the frame in place as you work.
3. Once you’ve got the frame in place, test the door to make sure it fits in the opening
4. Remove the door, screw the frame firmly into place, and remove the shims, unless they are needed to hold the door level.
5. Use a tape measure to find the hinge position and carefully notch them out.
6. Screw the hinge plates into the door, then move it into position in the frame
7. Fit the top screw in each hinge and screw it in. Once the top screw is in each plate, go through and add the rest but test the door regularly as you work, to ensure you have a perfect fit.
8. Once you have a smooth-working French door, fit the handle or doorknob, taking care to ensure that the strike plate and latch plate are properly fitted and flush against the frame and the door.

How Can You Pair French Double Doors?

French interior doors can be paired together in a couple of different ways. The way they meet can affect the functioning of the doors as well as the way they are installed, so make sure you decide how to pair them before you install them - or preferably when choosing the doors in the first place.

Square Meeting Stiles

If both doors have perfectly square edges that meet, this is called 'square meeting stiles'.This type of installation will leave a slight gap where the doors meet and this can affect the energy efficiency of the doors if not carried out correctly.

Rebated Meeting Stiles

French internal doors can also come in a 'rebated door pair'. This means they have slight notches or sections missing along the side where the door leaves meet. When they are closed, rebated meeting stiles will interlock creating a more solid join. This method creates a cleaner look and also lessens the chance of drafts getting through. However, the close fit can also make them daunting to install - this type of door has to be completely level otherwise they catch when opening. You will also need to know which opening direction you want before purchasing rebated meeting stile doors and buy your set accordingly.

Using a Pair Maker

If you have your heart set on a pair of doors with square meeting stiles yet also want the benefits of a rebate meeting pair, then you can fit your doors with something called a pair maker. This is a piece of timber moulding which you fix to the edge of one of your door pairs. A pair maker will create the illusion of rebated stiles, making a neater join and a barrier to reduce drafts.

How Much Gap Do You Leave Between Internal French Doors?

When you install a square French door pair you should leave a gap between 3mm and 5mm where the doors meet. This will leave enough space for your new doors to open and close without the two doors catching on one another. With rebated stiles, you don’t leave any gap, as the notches in the door account for the opening.

Is It Hard to Install Interior French Doors?

Installing a set of interior French doors is not a complex job. It can be time-consuming and even fiddly but it should be easy enough for anyone with basic DIY experience to do themselves. If you decide to tackle the job yourself though, you shouldn't try the job alone. Internal door slabs can be very heavy - particularly solid-core doors and ones with large glass panels. In order to get your doors installed you will need to move them around a lot so having an extra pair of hands to help you manoeuvre them is a must. If you don't feel confident with the job, you can always pay for a professional to fit your internal French door instead. It shouldn't take them long to get the job done, and you will get the added peace of mind that your French doors will function at their best.

Are French Doors, Bifold Doors or Folding French Doors Easier to Install?

A French double door is a lot easier to install than bifold doors. One of the main reasons for this is weight, as bifold doors with 2 or more leaves will be a lot heavier and harder to move around than each of the single-leaf French doors. The process to install folding doors is also harder. With French doors, it is the same basic steps as installing a single leaf door slab, with just a few minor adjustments. Bifold doors need a track fitted first, which is a very different process - see our guide to installing bifold doors for more information.

Can I Install Internal French Doors Myself?

While you can generally install a French door yourself there is one time you should definitely get the help of a professional. When you are installing French doors for the first time into a concrete wall without a suitable rough opening, you must get professional support. You should never make an opening bigger than 3ft wide in the wall of your home without using supports in case it is load-bearing. Most door pairs are 5ft or broader, so you will need to install a beam or header above the door frame to support the rest of the wall (and the weight above it too). This is a much more involved job than simply sliding a new door frame into place, so enlist the help of a structural engineer if you're not confident in your ability to make such a large modification to your home.

How Long Does It Take To Install Internal French Doors?

Installing a single leaf internal door can take anything from 2-6 hours but it doesn't necessarily take twice that long to hang French doors. Once the doors are cut to size, it is unlikely to take a lot of extra time - the only additional task is notching out and attaching a second set of hinges. What may take slightly longer is the preparation stage. With double doors it is even more important you get the door and the frame level to make sure your doors function properly.

How Do You Fit Internal French Doors With Side Panels?

When you install sidelights with your interior French doors, they will need to be fixed to a frame on all sides. This means it is easier to buy a pre-made frame or frame kit to house your sidelights when you buy your door. Many manufacturers sell sidelights and doors together with a frame anyway. It is not as common to use sidelights for internal French doors as it is for external doors, but it is always an option when you are trying to fill an unusually sized doorway. You just need to decide before you buy the doors if this is what you want to do and buy the appropriate kit. View our full range of internal French doors here.