Many people have a sliding glass door, usually in the back of their house where it can’t be seen. Although any door or window which is hidden from street view is a security weakness, burglars are thrilled when they see a sliding glass door (also called an arcadia door). That’s because sliding glass doors are particularly vulnerable to break-in’s. In most cases, all an intruder has to do is lift the door off the tracks. This will usually allow them to gain entrance, even if the door was locked, since the standard lock on these doors are usually nothing more than a latch. Watch this guy show you how easy it is to break into his own house when the sliding door is locked.
Some homeowners choose to wedge a dowel stick in the track, which actually works on any sliding glass track.. The benefit of this is that it’s cheap and effective. The guy at the home center store will even cut it for you if you give him the exact measurement. The drawback of this is that you have to bend over and wrestle it out every single time you want to unlock the door. Depending on how often you use it, this can be quite a pain.
The secondary issue is that your sliding glass door may not be anything more than a pending date with a big rock if the burglar is desperate enough. So, that expensive security system you installed isn’t going to go off if they break the window unless you have glass break sensors, which is definitely an option for under $100. But, if you don’t want to do that, you can put window film over the glass, so when that rock goes through the window, it doesn’t allow free access--burglars have to deal with the mess of glass and film, which can slow them down.
What else? There are a few options. One is to drill a hole through the top of the door and frame and insert a long sliding bolt through both. Or add a swinging bolt latch so the door can’t move even when they try to lift it off the track. Either of these can be disabled if they break the door with a lock, but they can just as easily break a window, which is where an excellent home security system comes into play.
There are other dowel-type locks and frame locks which are good options. The important thing is to have something, whether it’s one or both of these, because it might just be enough to send your would-be burglar on to an easier break-in.