Commercial burglars are becoming increasingly more aggressive in carrying out their attacks, using better tools that allow them to more quickly gain entry to your business. One common burglary technique is to force open an exterior door. In the past, this was usually done using a simple tool such as a screwdriver or knife, but we are now seeing burglars using tools such as 48” long prybars to force open doors.

Burglars often target doors behind or on the sides of the building as these are less likely to be seen by people passing by. On commercial buildings these doors are commonly hollow-metal doors secured by either a cylindrical lock, a mortise lock, or a rim exit device. To comply with building codes, most exterior doors must allow free exit from the inside with a single action, such as turning a lever handle or pushing on a push bar.

 

The thing that all of these locking devices have in common is that they only secure the door at a single point at the latch side of the door. When a burglar takes a prybar to the edge of the door, all of the force is applied to the latching device at this point. It is estimated that as much as 2,400 pounds of force is applied to the latch when a 48” prybar is used, and much more if the burglar leans onto the bar with his or her full body weight. Most latches (and the strike plate which receives the latch) cannot withstand this much force and quickly give way, allowing the door to be opened. 

 

One relatively inexpensive way to provide better security for the door is to install an interlocking security astragal along the edge of the door. This makes it more difficult for a burglar to insert a prybar and will likely discourage or prevent most attacks. (See Using Latch Guards and Astragals to Protect Doors Against Forced Entry).

 

For many businesses, simply installing an astragal is all that is needed. However, if a building is located in a high-crime area, or contains very valuable assets, additional steps may need to be taken to make the door even more resistant to forced entry. One way to do this is to provide additional points of locking along the edge of the door. This distributes the energy created when a tool is used to force open the door over a greater number of points, reducing the energy exerted on each point. 

 

One method of doing this would be to install a series of deadbolt locks at the top, middle, and bottom of the door. While this would provide better security, it would likely violate building codes because it does not allow free exit from the inside using only a single action. To provide additional points of locking while at the same time complying with building codes, equipment known as “multi-point locking devices” were created. These devices have bolts that secure the door in three or more points yet allow all bolts to be released at the same time using the single action of a lever handle or push bar.

 

Multi-point locking devices are expensive (~$1,600 - $4,000 USD per door) but are used on doors when a business owner wants an increased level of security for their facility and are willing to pay for it.

 

Multi-point locking devices are available in many different types and styles. Here are some of the most commonly used styles:

 

Option “A” - Surface Mounted Multi-Point Locking Device with Exposed Mechanisms

 

This type of device can be installed on an existing door. It consists of surface bolts located at three points along the latch side of the door. All three bolts can be simultaneously released when the push bar is pressed. Two additional stationary bolts are provided along the hinge side of the door. These bolts automatically disengage when the door is swung open.
This type of device is commonly used on emergency exit doors in back-of-house locations and in industrial applications where appearance is not of great concern.