Locksmiths can provide their customers with several types of door protection, depending on the application, the location and the customers’ input. Door reinforcements can be installed to resist unauthorized entry. To resist forcible entry on existing lockable doors and gates, customers can be upgraded with security strike plates, knob protection, hinge pins and latch protection.
Another area of door protection is to literally protect the door, jamb and locking hardware from carts, hand trucks and other movable units that can cause damage. Protecting the door can save a facility a significant amount of money, as a fire rated opening that is damaged often must be replaced. An example, a fire rated wood door that has the edge split because of repeated collisions must be replaced. Part of the replacement process is to have the opening inspected in order to be re-certified.
For this article, we will briefly discuss resisting forcible entry and spend the majority of the article on protecting the door, jamb and hardware.
Resisting Forced Entry
There are three basic ways a locksmith can improve resistance against forcible entry: by adding protection to strike plate area, the latch/bolt and lock areas and the hinged side of the door.
Security Strike Plates: Protection can be added to the strike plate area of inswing doors by installing a security strike plate. Security strike plates are normally installed into wooden jambs to prevent forcibly breaking the jamb in order to gain access. This oversized strike plate strengthens the jamb because of the increased length and additional mounting screws to secure the plate onto the jamb. The length of security strike plates range from about four or five inches to 18 inches or even longer.
Strike plates are normally made of 13 gauge or thicker steel in a variety of finishes. Single and double-hole versions are available. Single-hole models will normally have a center hole. Some security strike plates even have built-in dust boxes. Most double-hole security strike plates will have a 3-5/8”, 4” or 5-1/2” center-to-center dimension. These are the common spacings for most interconnected locks.
When installing a security strike plate, an important consideration is the length of screws. Most homes, apartments and condominiums have a ¾” inch thick wood door jamb that is mounted onto a series of 2x 4s. Often, there are spacers between the jamb and the wood framing to ensure the door jamb legs are plumb. Mounting screws should go through the jamb and into at least the first 2x 4. Use 3-1/2” or longer wood screws to install a security strike plate to be certain the screws go completely through the jamb and securely mount into the wood framing. To avoid breaking screws as they are being installed, drill full depth pilot holes.
Suggestion: If the latch side door gap is larger that 3/16”, you may want to surface mount the security strike plate, if the opening is not fire rated. Surface mounting the security strike plate provides a higher level of security by reducing the gap.
Latch Protection: Installing latch protection limits access to the area surrounding the latch or bolt. Latch protection is available for outswing and inswing wood, hollow metal and aluminum glass doors. For inswing doors, interconnecting metal parts are mounted onto both the door and the jamb. For outswing doors, there is latch protection only or latch protection plates cover part or most of the lock mechanism.
Hinge Pins: Hinge pins are installed onto outswing doors to prevent the door from being removed from the jamb by pulling the pins from the hinges or cutting the knuckles off. A hinge pin has wood screw threads on one end and the other end extends from the head in the shape of an unthreaded screw. The top of the hinge pin has a slot to accommodate a screwdriver for installation.
Latch protection products limit access to the latch and the bolt areas between the lock edge of the door and the jamb.
I was invited to the retrofitting of the lock hardware on a pair of wide stile aluminum doors equipped with rim exit devices latching onto a mullion.