Use a door barricade.
Securing french door from inside.
Install a commercial grade double sided deadbolt into the active side of the door or alternatively install a double side high security deadbolt into the active side of the french door.
However a deadbolt that locks both doors together and single sided deadbolts in the top and bottom of both doors are a good combination for securing both doors.
French doors are difficult to secure for several reasons involving the following weak spots.
Install a concealed lock for french doors.
For doors that come as a pair consider locking securing one of them permanently.
9 highly effective methods 1.
Add one side half deadbolts to the top and bottom of each door.
To do this we.
The stop should be 3 4 inch or thicker hardwood that extends the length of the door and overlaps the swinging door by 1 2.
This means anyone can remove the pins and take the doors off the hinges.
Because french doors have no center frame or support they are very weak in the center.
The best french door security will have a 3 point locking system.
Alternatively glue and screw a stop on the inside edge of the fixed door.
How to secure french doors from burglars.
Traditional wood french doors have many small panes of glass.
Out of all the locking options to secure a french door a single sided deadbolt is the best option.
My absolutely favorite method is the nightlock security door barricade from amazon.