Short answer
To secure a sliding glass door, block the lower track with a bar or dowel, add anti-lift blocks or screws in the upper track, and install a secondary lock such as a foot lock or pin. Laminated glass or security film slows entry through the glass, and a contact or glass-break sensor reports an opened door or breaking glass to the alarm.
In this article
Are sliding glass doors easy to break into?
Many sliding glass doors are easier to open than they look. The factory latch is often a small hook that can be pried or worn loose, and some older doors can be lifted out of their track while locked. The glass itself is also a way in. Each of these weak points can be fixed separately.
Sliding doors usually open onto a backyard, patio, or deck, which puts them out of view from the street and often behind a fence. That combination, a light lock in a hidden spot, is the reason patio doors come up so often when people look at what makes a house attractive to burglars. The fixes are usually small, and most of them do not require replacing the door.
How do you stop a sliding door from being forced open?
To stop a sliding door from being forced open, block the track so the moving panel cannot slide even if the latch fails. A cut wooden dowel or an adjustable security bar in the lower track does this. An auxiliary lock, such as a foot lock or a pin through both frames, adds a second point of resistance.
The bar or dowel should fit the track snugly with the door closed, leaving no room for the panel to move even slightly. A hinged bar mounted halfway up the fixed panel does the same job and is easier to use daily, which matters because the main weakness of track blocks is that people forget them. A worn or loose latch is worth replacing as well; if the door rattles in its frame when locked, the latch is not fully engaged.
How do you keep a sliding door from being lifted out of its track?
To keep a sliding door from being lifted out of its track, reduce the gap above the moving panel. Anti-lift blocks or screws set into the upper track leave enough room for the door to slide but not enough to raise it off the rollers. A pin lock through both frames also helps prevent lifting while locked.
A simple check shows whether this is a problem: with the door closed and locked, try to lift the moving panel. If it rises noticeably, it can probably be lifted further with a pry bar. Screws in the upper track should be set so the door just clears them; set too low, they scrape the panel and make the door hard to open.
How do you protect the glass in a sliding door?
The glass in a sliding door is usually tempered, which makes it safer when it breaks but does not keep anyone out. Laminated glass or a security film holds the broken glass in place and slows entry. A glass-break sensor or door contact on an alarm system is designed to detect the attempt rather than stop it.
Breaking a large pane is noisy, which works against an intruder, but a door hidden from neighbors reduces that drawback. Film is only as strong as its attachment to the frame; film applied to the glass alone holds the shards together but may still let the whole pane be pushed in. Curtains or blinds help in a quieter way, by keeping valuables near the door out of view.
Should a sliding glass door be connected to an alarm?
Yes, if the home has an alarm system, a sliding glass door should be part of it. A contact sensor on the moving panel reports when the door opens, and a glass-break or motion sensor nearby covers entry through the glass. A door hidden from the street, where forced entry would go unseen, benefits most.
Physical hardware slows an intruder down; a sensor helps make sure the attempt is noticed. The two work together, and placement depends on the room layout, pets, and how often the door is used. Sensors, contacts, and lighting for patio doors are planned during a professional security installation. For how doors fit into a wider plan, see our guide to preventing home break-ins.