Fixing French Door Locking Mechanism Replacement
You'll want to secure your french doors with security. This can be done by choosing the right lock that will keep your door secure while not hindering airflow or altering the appearance of your home.
French door locks typically have a three-point locking system that has flush bolts on the upper and lower edges of each door panel, and an opening lockset that can be opened. This system is difficult to break.
Fixing a French Door That Won't Lock
It could be a major security risk in the event that your doors do not lock or latch correctly. It could also be an indication of a serious issue such as a broken locking cylinder. Don't worry, the problem can be fixed with a few easy steps.

The reason a door won't latch is usually because of an obstruction that is blocking it. This could be as simple as a small piece of dirt stuck in the lock or it could be a problem with the latch itself.
If you examine the strike plate (the metal piece on the inside of the doors that sits against frame), you can see the truth. If you see a tiny metal tab sticking out of the strike plate, tap it gently using a screwdriver, then hammer it to bend it slightly and this will allow the hole to be opened in the plate so that bolts can be dropped into the door more easily.
A latch that has become stuck is usually due to poor alignment or installation. Lubricating the latch can help it work better, but will not fix alignment issues.
If you don't have a strike plate, it is easy to install one. The body of the lock (the part that screws into the door frame) must be removed from the door, and the lock assembly replaced. You'll require a Phillips-head screwdriver and a power drill for this, but it's not a difficult job.
It is recommended to keep the lock lubricated, especially the cylinder, frequently to ensure it operates as well as it can. You can use graphite or silicone-based oil to do this. Apply the lubricant on the key, and then turn it several times, slowly until the cylinder is able to move freely.
A double-cylinder deadbolt is better than a standard deadbolt when it is used on French doors. A simple twist lock on the handle won't be enough to keep intruders out, and a standard deadbolt fitted with a thumb-turn on the inside of the door could be beaten by breaking the glass and reaching in through it.
Repairing a French Door that isn't latching
Often the issue is caused by the door latch not engaging with the strike plate hole. This is usually due to hinges that are sagging, but it could also be due to the location of the latch or the latch itself. You can use lipstick, or another similar marker, to determine the cause. This mark will help determine the source of the issue. For instance when the mark is below the strike plate then it's probably the hinges. If it's above, then it could be the position of the latch.
It is important to be sure to align the strike plate and latch holes when installing handles or the lock mechanism on a French Door. This is particularly important when one door has been closed for a prolonged period of time. In this time the door may have moved. This is most common for doors made of timber and composite, as they are susceptible to expansion or contraction based on the weather conditions or the surrounding environment.
To fix this, take off the lock latch at the edge of the door that is active and unscrew it from the handle. Then, using a sharp chisel and hammer, increase the strike plate hole in the door frame. This will permit the latch to be put in a more suitable location for the door and when the door is opened and closed it will close smoothly without rubbing or catching the frame.
After the latch hole is enlarged, place the new latch into the strike plate and screw it in. Then adjust the strike plate with the hammer, screw and nut until it is in the proper position. Test the door. Make any adjustments as required.
The lock cylinder of external French Doors will not turn. This could be caused by obstructions or wear and tear, but it's usually easy to resolve. Often the lock is simply obstructed, or the pins in the cylinder are worn. It's worth trying to see if a simple clean will make a difference. If the issue persists, it is often necessary to replace the entire lock cylinder.
Fixing a French Door That Won't Open
If your French doors do not lock the way you want, the issue is most likely due to dirt and debris obstructing the lock mechanism. Verifying that the frame is free of debris and there is nothing obstructing the locking mechanism is the first thing you need to do. There might also be a problem with the alignment of the French door and its frame. This can cause the door to sway over the frame, which can eventually result in jamming.
The mechanism of the lock is fairly simple. The key rotates a spindle, which is then able to move a bolt back and forth on a rail. If the handle is moving but the bolt does not it means that something is stuck. It could be that the lock's mechanics are not working properly or it could need lubricating. Use a silicone spray. It comes with a nozzle can be used to direct the lubricant directly to the mechanism. Spray liberally and rotate the handle to ensure that the lubricant is reaching all the parts of the mechanism.
It is also possible to adjust where the latch is located on the French door. It is usually possible to do this from outside. If your French doors are new they will be capable of screwing the latch and handle into place without any problem. If your French doors are older, you'll need to use the template included in the lock kit to mark the location where the holes for the handle on the door and the latch on the frame must be. Make the hole for the handle or knob at the proper height. This is typically around 36 inches above the floor. Then, you can drill smaller holes on the outside of the door to install the latch.
After drilling the hole It is crucial to check that the latch plate is properly placed over the strike plate that is on the door frame. If this doesn't fit then the deadbolt might not retract into the strike plate when you pull the lever to lock. Finally, you will need to screw the latch plate in place.
Fixing a French Door That Won't Close
The latch on the latch of a French Door can get stuck and not close. Repair My Windows And Doors makes the doors inoperable. There's often a simple fix for this however it may require removal of one of the doors, especially when they're heavy. The most common cause is that the latch isn't aligned or with the strike plate or with the jamb of the door or both. It might also be that the dead bolt isn't fully extended or retracted fully. It is common for the dead bolt to misalign in time, as a result of weather conditions, or due to the shifting of the home.
It can be difficult to open doors that are stuck. To fix this you need to loosen the screws that hold the hinge to the frame and then, add shims to make the door raised or lowered. This will allow the latch to be closer to the lock mechanism and fix the problem.
Similarly, if the latch isn't in position with the strike plate's hole on the door jamb, you can usually fix it by loosening the screw that holds the strike plate and using a metal file or electric planer to remove some of the edge of the plate until the latch fits. This could also mean removing the strike plate and chiseling out the hole to make it bigger in the event that it is necessary.
Another issue that is common to French doors is that the locks don't engage properly. If you have a more recent lock it could be a sign of an issue with the cylinder that locks. If the lock is not functioning properly, you'll need take it off and examine for any visible damage.
If you have an older door with a draft coming in, consider replacing the weatherstripping that was used on the outside of the door. This will give a secure seal and help keep the doors from slipping or locking incorrectly. Door sweeps can be added to fill in any gaps. Install the sweeps on top and bottom of the door.