How to Install French Doors in an Existing Opening

If you've made plans to install a new set of French doors, you may have heard different advice from different people on whether you can do-it-yourself or need a professional. So, you may be wondering, just what steps are required to install French doors in an existing opening? After consulting with installation experts, we've provided the instructions below.
To install pre-hung French doors in an already built, rough opening, you will need to:
  1. First, remove the old frame and trim.
  2. Next, make sure the opening is square.
  3. Then, install the new frame. Test out the door, making adjustments as needed.
  4. Finally, finish securing the frame as needed. 
Read on to learn more about the steps for installing your French doors, how long it will take, and how much it costs to hire a professional instead. You'll also find options for picking energy-efficient doors and adding screens.
A modern dining room interior design with French door, How to Install French Doors in an Existing Opening

How Long Does It Take To Install French Doors?

If you decide to install the doors yourself, it shouldn't take more than a day. This doesn't include measuring the rough opening or ordering the doors (you may be waiting weeks for the doors to arrive). But once you possess the doors, the actual installation is typically between five or six hours. Sometimes, it can be as little as two hours - when the project is fairly straightforward, and no additional work is required.

Inevitably, however, there is almost always some issue that makes the process move a bit slower. Maybe the door trim is difficult to remove. Sometimes rot is discovered when the old door is removed and needs to be fixed. The rough opening may not be exactly square or need some work before the door aligns properly. Situations like these aren't uncommon for a door installation, which is why the project is rarely completed in just a couple of hours.

How To Install French Doors In An Existing Opening?

French doors installation in an existing opening guide, How to Install French Doors in an Existing Opening

1. Remove Old Frame and Trim

Removing the old frame takes around an hour. You'll want to score the caulking around the trim. Then pull it off with a pry bar, such as the one featured below.

Click here to see this pry bar on Amazon.

Prying will help you remove the frame without damaging the wall. Be sure to set aside the trim for re-installing later, keeping notes as needed to help you remember what piece goes where.

2. Square the Opening

In this step, you will need a carpenter square and a long level.

Click here to see this speed square set on Amazon.

Click here to see this Craftsman level on Amazon.

Use these tools to ensure that your opening is square - your door may not close or align properly otherwise. 

3. Install New Frame

Install the frame, adding shims as needed to level the door.

Click here to see these wood shims on Amazon.

Make sure jambs are flush with the wall. Nail through the frame and shims into the studs, just enough to hold the frame in place. Check the door at this point, ensuring everything is opening, closing, and working as needed.

4. Finish Securing The Frame

Finish securing the frame permanently, once you are certain everything is leveled, aligned, and opening and closing properly. Trim off any exposed shims with a box cutter or wood chisel like the one featured below.

Click here to see this three-piece wood chisel set on Amazon.

Finally, reinstall the trim (or cut and install new trim, if your project requires it).

Installing Exterior French Doors In An Existing Opening

The steps above are for an interior door installation. The same steps are included in an exterior door installation. However, you'll also need to put in flashing and a metal sill pan or membrane pan. These items are fit into the rough opening before the door frame is placed.

Once the door is fitted into place, you'll add weatherstripping and caulking. This needs to be done before you reinstall the trim. This video includes the weather-proofing steps required for exterior doors and will help if you still have any questions on the process.


How Much Does It Cost To Install French Doors?

Opened white French doors

French doors vary wildly in price. Factors that affect the cost include door material, locks, hardware, door swing (whether the door opens in or out), and the glass (both the type and style). Exterior doors cost a bit more than interior ones. Doors made for the exterior require special gaskets, weatherstripping, locks, and more durable construction. As a result, these doors range from $500 to $4,000 dollars. Custom options can be even more costly.
Hiring a professional to install your doors may be necessary for French doors. It can be tricky, and mistakes can cause leaks and misaligned doors. This will cost an extra $400 to $1,400.
Interior doors do not need all the same extras. This means they are more affordable, and simpler to pick out. They can cost anywhere from $50 to $1,000 dollars, on average. The cost of installation by a professional is usually between $150 and $500.

When To Hire A Contractor?

Builder in uniform installing a door lock into the entrance door of a new house

For someone who is relatively good at construction projects, installing French doors is certainly possible. However, there are some factors to keep in mind. The following concerns may help you determine if this project is within your skillset, or best left to a professional.

Interior or exterior

Exterior doors require weatherproofing. If you understand the extra demands of an exterior door, it's still worth noting that many people think French doors are more difficult to seal correctly. If you've never installed an exterior door, this probably isn't the time to learn. 

Door Style

Most people automatically assume that French doors are a set of double doors, but they don't have to be. French doors are also available as single, bifold, or sliding doors. If you've installed doors in the same style as your new French doors, the new ones shouldn't really be any harder just because they're French doors. For example, a single French door is very similar to installing any single door. A double French door is tricky because of the alignment of both doors - but if this isn't your first attempt at a double door, there is really nothing to worry about.

Do French doors Add Value To The Home?

A white French door entrance to a living room with view of the front yard

French doors are recommended as one of the most effective ways to add value to your home. Because they bring in more light and make the room seem bigger, a house with French doors can sell for a higher price. However, because French doors can range so much in price, a homeowner should select doors carefully. The more costly options may be an investment that you can never recoup.

Stick to quality, traditional French doors. Don't bother wasting money on expensive custom options, which may not appeal to the taste of future homebuyers anyway. Custom doors really are only a good choice when they are for your own enjoyment.

Are French doors energy efficient?

French doors have come along way in recent years. Modern doors are very energy efficient, with new and improved options available. This means that French doors can make up for your initial investment by saving you money on lower heating bills. 

Plastic window profile with triple glazing

Some options to consider when buying doors include using doors that use argon-filled glass, new Low-E glass, and dual or even triple-pane glass. Be sure to ask for information on the Energy Star rating of any doors you are considering. 

Can You Put Screens On French Doors?

Double white framed screen door

French doors do pose some problems when it comes to screens. If you use a traditional screen door, you'll need room for both the glass and screen doors to swing open, in both directions (one will swing in and one will swing out). For some people, this isn't a problem. However, in a lot of setups, that much room simply isn't available.

To solve this problem, door manufacturers have come up with several options that ensure you can find a screen to work with your door. Two common possibilities are retractable screens and magnetic screens.

Retractable screens install on either side of the door. It rolls up into a concealed space in the doorjamb. When you're ready to use the screen, you just pull it out.  It moves across a track, similar to a sliding glass door. Both sides of the screen open up until they meet in the center.

Click here to see this retractable screen on Amazon.

A less permanent fixture is magnetic screens. They simply hang in front (or behind) the door. You'll just push the screen aside in order to open or close the door as needed. This works well in homes with pets, as animals can also push the screen aside. This screen allows them to come and go as they please. 

Click here to see this magnetic screen on Amazon.

To Summarize

Installing French doors usually takes five or six hours, including removal of the old frame. A very simple installation may take only a few hours. However, complications aren't unusual and will add to the duration of the project. Many people opt to have a professional install their French doors, as they can be tricky to do correctly. Mistakes can lead to leaks, water damage, and misaligned doors. 

For further reading, try:

How To Add Shade To A Porch? [15 Solutions]

28 Awesome Porch Railing Ideas

One comment

  1. French doors are the most secure form of doors as there is only one opening handle from inside, hence providing security to the home. These doors can give your home a beautiful, open look to a home.Thank you so much for giving detailed explanation for installing french doors in an existing opening.I find this post truly useful.

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