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How to Lock a Sliding Glass Door From the Outside?

Fact checked by Teddy B.Miller

how to lock a sliding glass door from the outside

Sliding glass doors are not designed to be installed as front doors, but that does not mean they will not work well as one. Many homeowners install this type of door for their house’s entrance with added security. So, the only question here is, how to lock a sliding glass door from the outside to guarantee house protection?

If you plan to lock a sliding glass door from the outside, it is necessary for a lock with key installation. With a lock plus a key on your sliding glass door, you are guaranteed peace of mind and utter use when locking them from the outside.

So, this article will help you with detailed instructions and offer further advice on this type of door.

What You Will Need to Follow this Tutorial


In order to add an outside key lock for sliding glass door, you will need to take into account these instructions. As we have mentioned earlier, they may appear difficult for inexperienced homeowners. But our detailed guide will be helpful.

  • Mounting an exterior key lock for the sliding glass door
  • Mounting a sliding glass door lock for extra protection

Step by Step Instructions

Mounting An Exterior Lock For The Sliding Glass Door

As you install the glass door or your house’s entrance, you should install a lock for unlocking your door from the outside and an extra lock for protection against burglars and prevent small kids from opening it.

Step 1: Wash the sliding door

Mix a simple solution of soap and hot water to clean the frame first. Make sure all the remaining dust and dirt are washed off your door and its frame. After cleaning, you may leave the door air dry, preferably wipe out the moisture with a soft towel for quicker drying.

Step 2: Determine the right spot

You can do this by placing one ear near the door, then use a screwdriver’s plastic end to knock it until this sound changes. It means there is no glass behind this door frame.

Step 3: Mark this spot


Once you have found a spot without glass, mark it with a piece of chalk or a marker. Later on, you will have to place the new lock against this site and mark the safe spot and where to insert the screws through your sliding door.

Step 4: Install your new lock


Place a punch made from metal on your previously marked spot on the frame. In order to make a hole, hit the punch gently using a hammer. Continue drilling until your lock has sat tightly inside. Next, fix your door lock firmly, so it is in position with the mounting screws.

Step 5: Mount the latch plate

After mounting the sliding glass door lock, it is time to install its latch. Mark a spot on your door frame for this latch plate. Then, drill essential holes and secure this part to the frame.

Step 6: Check the lock’s performance

In case your newly installed lock does not work, you will likely have to adjust its latch. This is to make sure it has entered the right spot for the sliding glass door locks.

Mounting A Sliding Glass Door Lock For Extra Protection


Without a doubt, the most helpful method for sliding glass door security is a compatible lock. You will mount this lock at the door top, the meeting point of its stationary glass, also your sliding glass door.

Although this type of lock is mainly for interior applications, some need a key for unlocking, allowing you to mount it on the outside.

A lock for sliding doors is a helpful addition to other locks. It has the advantage of being opened by grownups and tall enough children only. Also, it stops people from budging the door open with a jimmy, both from the inside or outside.

Typically, you will find 2 types of locking positions for this lock: the first is being entirely locked, while the other lets you close this sliding glass door around 3 and 6 inches for air circulation.


The instructions will vary since it depends largely on which type of sliding door lock you buy. That is why we will offer basic instructions for you to understand the things involved during this procedure.

However, it is recommended to follow the manual attached to your purchased lock to ensure a smooth installation.

Step 1: Clear the debris


Close the sliding glass door completely and wash off any dust and dirt from its upper track.

Step 2: Install the lock

Put your new lock into a suitable position. Mark some spots for hole drilling. Use a drill to make holes, then mount your lock on that area.

Step 3: Mount its side piece

Fix its top to the door’s top track. Apply the same process for securing the locking part on the door’s glass. Make a quick check to see whether your lock has entered the contraption’s other part and your key is functioning alright.

Read more: Detailed guide to installing a new sliding barn door lock

Additional Measures for Sliding Glass Door Safety


Apart from installing regular locks, we would like to introduce some other useful methods for your locking sliding glass door from outside, including mounting extra locks and applying a one-way film. Check out our suggestions below.

Install Extra Locks

Having security bars for your sliding glass patio door is awesome for security, especially when they come with an anti-lift lock. This horizontal bar is placed on the hinge to prevent your door from sliding and getting opened. Some locks might be secured either at the door’s top or bottom.

When you turn a key, the pins inside these locks will either move into the top or lower door frame to keep your glass door from sliding. You can install double bolt locks to increase the overall security of the sliding glass doors.

Add One-way Film

Have you ever thought of applying some one-way film sheets? You can place them on the sliding door’s glass area as they allow you to observe things outside and prevent outsiders from looking in at the same time. These people will only see their reflections in this mirrored finish.

Remember that this type of film is only effective for daytime use. During the nighttime, you would still have to close the window blinds or the curtains.

You can check out this video for more information:

Frequently Asked Questions

Here are the most frequently asked questions related to locking a sliding glass door from the outside.

How does a sliding glass door work?

This sliding glass door lock is often activated by an internal spring. As you unlock this door, the innerspring of the bolt will contract and force the door open. And when you close it, your action activates this spring, then releasing it and lock your door.

Are smart locks available for sliding glass doors?

If you are not certain about installing regular locks to lock sliding door from outside, you can consider smart units. Most of them are the surface-mount type of lock produced by the USA-based company, Lockey.

The most famous option you can get from this brand is the Lockey 2500. After a successful lock program, it automatically locks your sliding glass door.

Is it possible to install a keypad lock for sliding doors?

Besides smart locks, many homeowners mount a keypad lock for outdoor use on their sliding glass doors. It can be a perfect and safe addition to your other lock types to gain more security benefits.

But if you mount the keypad lock using a hook bolt, it will not be necessary to place a stick between the doors to prevent it from being unlocked without permission.


Without a doubt, security is important for every home. Thus, you have to find ways to lock a sliding glass door from the outside effectively, whether it is meant to protect children or prevent unwanted intruders.

When you go shopping for a sliding glass door lock, check out each of their features carefully. Regardless of the product choice, it should be a unit that you can use easily and efficiently, not something too difficult to operate.

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