Commercial Security Hardware: It All Starts With The Door

The jamb is the frame surrounding the two sides and top of the door. The threshold is located below the bottom of a door mounted into the finished floor. Between the bottom of the door and the threshold is the sweep or door bottom. The sweep is mounted onto the bottom of the door. Sweeps and door bottoms can come preinstalled onto the door or can be added later.

The door, jamb and the threshold work in conjunction with the weather stripping. Weather stripping is a seal that surrounds a door to keep out the elements. A properly sealed door helps with heating and cooling costs.

Weather stripping can be as simple as rubber, foam, vinyl or plastic. There are also smoke seals, designed to keep the smoke and fire from traveling.

If there is a pair of doors, additional hardware can include a door coordinator or a mullion (vertical support). Door coordinators are designed for pairs of doors to have the inactive door close first, then the active door when both doors are opened. Coordinators are designed for high traffic commercial projects.

Pairs of doors that swing in the same direction may have either an automatic flush bolt or a manual flush bolt to lock the inactive leaf (door) in place, so it will not open before the active leaf has been opened. The automatic flush bolt locks the inactive leaf when the active leaf is closed; unlocking when the active leaf begins to swing open. Manual flush bolts must be physically locked and unlocked. Flush bolts are available for the top and the bottom of the door.

Depending upon the swing of the pair of doors, an astragal may be installed. A vertical molding attaches to the swing edge of active leaf of a pair of doors. The astragal can provide security protection as well as protection against weather and to minimize the transmission of smoke, light, etc., between the doors.

The method of mounting the door onto the jamb can be accomplished using a continuous hinge, butt hinge, or a pivot. Butt hinges are the most common method of mounting a wood or hollow metal door onto the jamb. Butt hinges are available in steel, brass and stainless steel. They can be ordered with decorative tips, non-removable pins, ball-bearings, etc. The hinges are measured by the height and the open size. Door height and weight determine the size and number of butt hinges mounted onto a door.

DOOR CLOSERS

Door closers are mechanical devices that close doors. The standard door closer stores the energy used in the opening of the door and releases it to close and latch the door. Common closers are equipped with hydraulic dampers that control the speed at which the door closes.

An important consideration when installing a door closer is to install the same closer that was removed or a closer with the same mounting hole pattern. This is because if the door closer is installed using sex nuts, having two sets of holes (eight) on the opposite side of the door is not very appealing. An alternative is to order a retrofit plate. The retrofit plate is mounted onto the door using the existing holes and the closer is mounted onto the retrofit plate using the new hole pattern. This eliminates excess holes.

Important: Before installing any additional hardware onto fire labeled doors, be sure to contact the Local Authority Having Jurisdiction.

THE LOCK

Finally the most important piece of hardware mounted onto a door is the lock.

A mortise lock requires a pocket, either precut by the door manufacturer or cut into a wood door. Installing a mortise lock into a blank wood door requires woodworking skills as well as tools such as a mortise jig or auger (wood) drilling bits. Mortise locks consist of a lock body (inside the door), the lock trim and usually one keyed mortise cylinder.

The advantage of a mortise lock is the wider range of other manufacturer's lock cylinders.

Cylindrical locks have advantages also. In most instances, different brands of cylindrical locks can be installed into the same door prep without having any modifications. The only issue that can occur is if the replacement cylindrical lock's rose is a smaller diameter than the existing lock. If the door has been painted with the previous lock mounted, there will be a ring of the previous color surrounding the rose of the new lock.