Sliding glass doors can be a big security risk.  They represent a common entry point for thieves because of some inherent vulnerabilities.  However, you can address these relatively easily and quickly by installing a sliding glass door lock in order to harden this part of your home.

The first thing to do is to ensure your sliding glass door is installed correctly.  Don’t laugh, some doors are installed backwards, meaning the sliding part is on the outside of the frame rather than on the inside.  This allows a thief to lift the sliding (outer) panel off the tracks and enter the house without breaking anything.  So the first thing to check is if the sliding panel of the door is on the inside track.  If it is, it has been installed correctly.  If not, the panels will need to be swapped so the outer panel is fixed and the inner panel slides.  Once that is done, you will need to install a secondary lock on the sliding panel.

The locks that come with sliding glass doors are not very robust, especially older ones.  Most door locking hardware is not as robust as modern deadbolt locks because the mechanisms are smaller and have less contact with the latch on the door frame.  Thieves can pry a door open by breaking the lock with a crowbar and force because the locks aren’t strong enough to resist forced entry.

There are several methods one can use to secure a sliding glass door.  If a sliding glass door is installed correctly, removing it vertically by lifting it off the tracks is all but impossible.  The vulnerability is horizontal movement, so I installed a lock which prevents sideways movement when engaged.

For less than $20 each, I purchase these locks for my sliding glass doors and had them installed.  They mount to the sliding frame and have a metal pin that goes into a slot that is drilled into the upper part of the door frame.  When engaged, this lock prevents lateral movement even if the door latches are compromised.  If the thief still wants to break in, he will have to shatter the glass and risk making noise in the process.

While installing a lock won’t prevent break-ins, they will make your home less vulnerable.  The key to home security is not making your domicile invulnerable, its to add multiple layers of protection that will discourage thieves.  Criminals generally look for easy targets to attack, by hardening your home with sliding glass door locks, you make your home an uninviting target.