An installation is only complete when the appropriate security hardware has been installed. The job is not completed with just the installation of a high security mechanical or electro-mechanical latch or deadbolt lock. We must take into account the traffic, location, materials and construction of the opening, plus the interaction between the door and the jamb to determine the correct hardware.
Is the door being serviced susceptible to vandalism or forced entry attacks? By code, most exterior commercial doors are required to open out. This places the latching mechanism in view from the non-secured side. To make matters worse, many doors are either installed incorrectly or have changed because of settling, time or natural affects. The security of the opening decreases when the gap between the lock edge of the door and the jamb exceeds 1/8”.
If there is a wide gap and the strike plate has not been properly mounted, the door can possibly be opened by manipulating or cutting the latch or bolt. On center hung doors, the deadbolt can often be cut, as there usually is no protection to prevent sawing.
For most wood and hollow metal doors, a jamb stop deters sawing of the deadbolt. However, if the gap is wide enough, a battery operated rotary grinder can be used to gain entry.
On doors that are equipped with latch mechanisms, the latches can be slid back using different methods. My favorite easy entry is to “loid” open the door, a method that was introduced more than 50 years ago. Loiding uses a thin piece of plastic or film to slide between the tip of the latch and the strike in order to be able to open the door. This method will work on spring latches and dead latches where the dead latch extends into the opening of the strike plate. The term loid comes from the word celluloid (film), where a piece of 35mm movie film could be used to open a locked door.
To protect against loiding and other forms of attacking the latch or bolt, a variety of products have been introduced over the years using many different names. These latch protection products limit access to the latch and the bolt areas between the lock edge of the door and the jamb. Some of these include the names guard plates, latch guards, astragals, vandal guards, latch protectors, anti-vandal handles, etc.
In many instances, these terms are interchangeable. However, the basic design is to obstruct the lock edge of the door, covering the exposed portion of the latch or bolt. In addition to protecting the latch or bolt, these devices can also provide some protection for the exposed portion of the rim or mortise cylinder. As example, Major Manufacturing sells an aluminum door guard plate that provides protection for the latching mechanism and the lock cylinder.
For some exterior doors, such as electric room doors or vandal prone areas, there are latch protectors with lock cylinder wrenching protection that have built-in handles. These handles eliminate the need for exterior trim. Trimco manufactures Anti-Vandal Handles in a number of configurations.
For our purposes, this article will use a description “Latch Protection” instead of a specific product name. Latch protection is available in different sizes and shapes to accommodate different door and jamb configurations and composition as well as different strike plate types and locations. Latch protection is available in varying thicknesses and different materials. For example, Don-Jo offers stainless steel latch protection plates for out-swinging doors.
The construction and swing of the door, its location within the jamb and the type of lock, strike plate or electric strike and finish determines the latch protection. Latch-Gard products are available in several different finishes to match the lock hardware.
For example, if an out-swinging wood or hollow metal door located along the forward edge of the jamb (flush) is equipped with a latch bolt function mortise lock. The lip of the strike plate extends beyond the jamb.