how to install a locking system for french door

locking system for french door
Tools Needed
1 Deadbolt
2 Masking Tape
3 Pencil
4 Spade Drill
5 Electric Drill
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Materials Needed
1 Screwdriver
2 Hole saw
3 Wood chisel
Total Cost
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Estimated Time
1-2 Hours
Skill Level: Advanced
The total cost and duration may vary when hiring a handyman!

Project Overview

lock for a french door

Sophistication, style, and ambiance are all characteristics given to your home after French doors are installed. Some French doors are pre-set with a lockset, however, if the door you’ve purchased is without one, it is up to you to add a lock. French doors are beautiful, but they’re not very secure, particularly without a lock. Luckily, a lock is an easy addition to a French door. After install, enhanced beauty and intrigue are enjoyed inside the home, as well as the added security and protection needed for comfort and peace of mind when you’re home and when you’re away.

Several types of locks can be easily added to a French door, but the deadbolt is the most popular of the options. Learning more about the different type of locks to determine which is best suited for your door is the first step in gaining these amazing attributes. With the information in tow that you’ve learned, choosing the best lock for your needs is simple.

No professional is needed to install locks on your French doors. Once you know the type of lock you want to install, use the step-by-step instructions below to learn how to install a locking system for a French door in about half-day.

Step-By-Step Instructions


Purchase a New Lockset

new french door locks

Set your lockset budget before traveling to the home improvement store. Knowing the amount of money you can spend on a product before arrival lessens the hassle of shopping and minimizing the time you’ll spend inside the store selecting your new lockset. Visit your local home improvement store to purchase a new lockset for the door. Many types of locks and locksets are available to install on your French doors. Talk to the home improvement specialist about each type of deadbolt lock, but do plenty of research concerning the lock types before the date of purchase.

Locksets are sold in prices low and high, each offering something different than the next product. With the help of an associate, you can determine which lockset is best suited for your needs. Remember, a high-quality, durable lock purchase is important to keep your French doors secure! Choosing a lock utilizing a three-point locking mechanism provides the best security possible for this door style. Should you wish to permanently shut the door, it’s possible with a deadbolt that has a sliding lock on both the top and the bottom of the door. To permanently secure the door, causing difficulty forcing the door open, drill a hole into the locking mechanism and use a wood screw to cease the door from opening.


Drill The Hole

french door locking system

A template is included with the deadbolt lockset package that you buy. This template provides exact installation instructions for that particular lock. Use tape to secure the template onto the door for easy reference. The template has many holes in it that indicate where parts of the deadbolt should be attached. The largest hole on the template is the location of the main body of the lock. The doorknob or the door handle is placed here. A large pivot hole is necessary to secure the door knob or the handle.

Use your drill to create this hole. Ensure the pivot hole that you drill extends through the thickness of the door material. After you’ve made the pivot hole, it’s time to finish making the hole for the doorknob! Use your hole saw to drill this hole. It should extend about halfway through the door. Moving to the opposite side of the day, repeat the process. When you drill the holes in this manner, wood splintering risks are reduced.


Install The Latch

French door locks

Using the template provided with your deadbolt, drill a latch hole in the door with a spade drill. There’s a few more screws to drill to set the door lock. A screwdriver or drill will secure the screws on the door edge and those on the door face. How long are the screws on the hinges of your French doors? If these screws aren’t three-inches long, consider updating them now to enhance security, since this screw length secures the doors to the doorframe. Also ensure there’s a one-inch throw on the deadbolt to make it more difficult for intruders to force entry into your home.

The deadbolt should now be placed into the latch hole. Use your pencil to trace an outline of the latch plate on the edge of the door. A mortise for the latch plate is also needed. Use screws to attach the plate into the mortise. If you’re unsure how to cut a mortise on a door, simple screw the hinge to the door jamb, score an outline with a utility knife and again remove the hinge. Place the chisel on the score you created, bevel side facing the mortise. Then, lightly tap the chisel using a hammer to create a deeper scored line. Make cuts ⅛-inch apart with the chisel. Lay the chisel flat and use to clean out the waste from the new mortise cut. When finished, the mortise should be the same depth as the hinges.


Install The Lock Body

locking systems for french doors

Use the template and instructions included with the lock to set the lock body. Installing locks varies considerably, depending upon the type and brand of locket you purchase. Most deadbolts require assembly by simply attaching the inner and outer cylinders together with screws. Before tightening, ensure the lock and key are working properly. If you’re adding a lock to a metal or fiberglass door, use a carbide-tip drill to create holes in the material.

Position the deadbolt so that it aligns with the adjoining door edge of the stationary door. Close the door one-fourth of the way; marking the position. Mark a score around the strike plate with your utility knife. Create a mortise with the chisel, placing the strike plate inside. Mark the hole for the deadbolt and drill the hole into the stationary door. If the hole is not the same length as the deadbolt, adjustments should be made. When the hole and deadbolt are the same length, screw the screw plate into the mortise.


With a lock installed on your French doors, home security is now improved considerably and peace of mind and comfort are two qualities you’ll enjoy when you’re home enjoying time with those that you love, and when you’re away at work or elsewhere. To further protect your home from intruders, a security bar can easily be added to the French doors. A security bar reaches from the door to the floor, preventing it from opening. There are some security bars with alarms included.

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