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How to Lock French Doors Interior in Only 3 Easy Steps?

Fact checked by Teddy B.Miller

how to lock french doors interior

Want to know how to lock french doors interior? Mark the holes on the door and the door jamb using the template. Drill a hole in the door using a hole saw. For the door jamb, chisel out a portion that will fit the base plate. Drill a hole that is deep enough for the bolt. Install the bolt and secure it with screws.

You must have the right interior french door lockset to secure your home. A good lock for french doors is a flush door bolt. By following this tutorial, you can install the piece by yourself.

What You Need


Before you can start with the tutorial, there are items that you need to prepare first. Some of them may already be available in your toolbox. If not, you can purchase some of them at the store.

Flush bolt


One of the most common locks for french doors is flush bolts. Usually, a flush bolt is installed on double doors where one of the doors is inactive while the other is moving. To keep the door close, the bolt is recessed into the door edge and it is moved upward and downward into the door jamb.

Before purchasing a flush bolt, you must first check the size of your french door and its overall height. Also, determine if it has square or round corners. You must be sure that a flush bolt can be installed into it.

Chisel and Hammer


The best tool for creating a mortise is a mortise chisel. It can withstand heavy blows from a mallet and it can cut across the grain. In choosing a mortise chisel, the sides must be slightly beveled and it has good-edge holding characteristics.

To prevent the chisel from cutting into materials, you need the right kind of hammer that is twice the surface area of the head of the chisel. Also, the hammer must be heavy enough to make the chisel work. You can use a ball pein hammer since it is used for objects like chisels. It has one flat end and a round end.



Since you need to mark the wood, a pencil is needed. You can use a carpenter’s pencil because it is designed for creating accurate marks on wood, concrete, and other kinds of materials.

Compared to a regular pencil, this one does not roll around on work tables or floors because of its flat body. The three types of lead you can choose from are soft, hard, and medium. If you don’t have a carpenter’s pencil, you can also use a regular pencil to make sure that its lead is hard enough to make a clear mark.

Power drill and Hole saw


You need to use a power drill to make a hole in the door. You can also use it to turn the screws by replacing the bit with a screwdriver tip. You can choose a corded drill that has power that reaches up to a 110-volt electrical cord. If you want to move freely while drilling, you can use a cordless drill since it is powered by a battery.

Aside from a power drill, you also need to have a hole saw. It is more efficient to use than drill bits because it can make larger holes. There are different sizes of hole saw so check in the template the sizes of the required holes to determine the size of the hole saw that you need.

How to Lock French Doors Interior


Step 1: Determine the position of the bolts and mark the holes

Before marking the holes in the door and the door jamb, you need to determine where you want to install the flush door bolts. Once you are done with this, you can now mark the required holes using the template as a guide. Make sure to use the pencil to mark in the exact place.

Step 2: Drill the holes

After having marked the holes, you can start with drilling. Drill a hole at the door using a hole saw. For the door jamb, chisel out a portion that will fit the whole base plate then drill a hole that is deep enough to allow the bolt to go through it.

Step 3: Install the whole bolt

You should start by installing the base plate on the door jamb. Before that, you must first drill the holes for the screws. Once done, you can now insert the base plate into the mortise hole and secure it with screws.

For the door bolt, place it on the hole that you cut on the door earlier. The bolt must fit properly in the hole. If not, you can chisel out the hole until the bolt rests evenly on the door. Drill holes for the screws and position the flush bolt. Secure the bolt with screws.


Do you enjoy our tutorial on how to lock french doors interior? You can now lock your french door for your security and privacy. There are also available door knobs for french doors that you can add to improve your safety and also enhance them aesthetically.

If you find this article useful, you can share it with your friends and loved ones who are wondering how they can lock their french doors interior. You are also welcome to share your thoughts regarding this tutorial. Leave a comment below.

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