5 Types of Common Commercial Door Hardware for Double Doors
Commercial doors can be provided as single door openings or as a pair of doors, also called double doors. Double doors can have some unique commercial door hardware items that aren’t used for single door openings.
The 5 types of commercial door hardware we will be discussing in this blog post are:
- Flush Bolts
- Mounting Brackets
- Removable Mullions
These commercial door hardware items won’t necessarily all be used on the same set of double doors, but they all perform a unique function that can be critical to the proper operation of a pair of commercial doors.
Flush bolts get their name for how they are installed. Flush bolts are installed in the vertical edge of the door opposite of the hinge edge. They are flush with the edge of the door. Bolts project vertical up into a strike in the frame and/or vertically down into a strike in the floor beneath the door.
Flush bolts are always installed in the inactive leaf of the pair of doors. Flush bolts are meant to hold the inactive door secure when the door is closed.
Flush bolts can be manually operated, semi-automatic, or fully automatic. Manually operated flush bolts will have a small mechanical lever that will project or retract the bolt.
Semi-automatic flush bolts are manually retracted using a mechanical trigger and will then re-latch when the active leaf closes.
Automatic flush bolts will both retract and re-latch by itself. A small trigger on the edge of the auto flush bolt is actuated by the active door. When the active door opens, the trigger is released and the bolt will retract allowing operation of the inactive leaf. When the doors close, the edge of the active door will push the trigger into the edge of the automatic flush bolts and project the bolt into the strike.
Double Door Coordinators
Coordinators are only used on double doors with door closers installed because, as the name implies, it will coordinate the closing of the doors. The inactive leaf on a pair of commercial doors will usually need to be closed before the active door. Coordinators will automatically coordinate the closing of doors so that an individual passing through the opening is not required to ensure that the doors close in the proper order.
Often the active door leaf will have latching hardware installed that latches into a strike that is installed in the inactive leaf. If the doors do not close in the correct order, then the door can potentially be left unsecured.
There are a few different types of coordinators. The most popular type of coordinator is a coordinator bar that is installed at the head of the frame and faces the door from the push side of the opening. There are two triggers on either end of the coordinator bar that are depressed as they come in contact with the face of the door. To coordinate the closing of the doors, the trigger that faces the inactive door will hold the inactive door leaf open until the active leaf pushes the trigger on the other end of the coordinator bar.
Coordinators are usually required on double door openings that are fire rated and have door hardware that needs to be opened and closed in a certain order.
Mounting brackets are only used on double doors where a coordinator bar is used and the closers will be installed using parallel arms. Because parallel arms are fastened to the soffit on the head section of the door frame it causes conflict with coordinator bar. This is because the coordinator bar is also installed to the soffit on the head of the door frame.
Mounting brackets are used to prevent the fasteners of the closer from entering the coordinator bar and damaging it’s internal mechanism.
Mounting brackets come with holes for fastening the brackets to the frame and there is generally a blank plate portion that allows you to drill the holes needed for the parallel shoe hole pattern.
Overlapping astragals are installed to the edge of one of the door leafs, either the active or inactive door, and extend enough to overlap the edge of the other door. This type of astragal should only be used on double doors where the doors open in a certain order (i.e. active leaf opens first, then the active leaf).
If an overlapping astragal is used on a pair of doors that open independently of one another (i.e. double doors with vertical rod panic devices installed) the astragal will prevent one of the doors from opening when it should!
This brings us to the other type of astragal, the meeting stile astragal. These astragals have two parts, installed on the meeting stile edge of each door leaf. The two pieces of the astragal will meet in the middle to seal the gap when the doors are closed. These types of astragals will allow the doors to open independent of each other when needed.
Removable mullions are often confused with astragals. This is often because they also seal the gap between the doors when they are closed. However, removable mullions are often used on openings to provide added security. They are more durable and allow for rim panic devices to be installed on both doors.
Removable mullions can be keyed removable, which requires a keyed cylinder, or they can be simply mechanically removed using a special tool. When large machinery or office equipment need to be moved through the opening, the mullion can be detached from the frame and then reattached as needed.
These are some of the most common types of hardware used on double doors. There are endless combinations and unique applications for double doors as well. Talk with us at Beacon CDL to determine the right hardware for your commercial doors.
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