What is the difference between the active leaf and the inactive leaf on a double door?
The active leaf is the primary operating door used for daily traffic. It carries the lockset or primary exit device and swings freely without releasing any bolts. The inactive leaf remains closed most of the time and is secured by flush bolts or a surface vertical rod exit device at the top and bottom. The active leaf always closes second when a coordinator is present.
When do I need a door coordinator on a pair of doors?
A coordinator is required whenever a pair has an overlapping astragal. The coordinator ensures the inactive leaf closes first so the astragal overlaps correctly and the active leaf latch can engage. On fire-rated pairs, a coordinator is mandatory per NFPA 80. If the pair has no overlapping astragal and no fire rating, a coordinator may not be necessary.
Can I use two rim exit devices on a double door opening?
No. Two rim exit devices on a pair create a latching conflict at the meeting stile because both devices attempt to latch horizontally with no fixed strike point. The correct configuration is a rim exit device on the active leaf and a surface vertical rod (SVR) exit device on the inactive leaf. The SVR latches vertically into the frame head and floor.
What type of flush bolts are required on fire-rated double doors?
Fire-rated pairs require automatic (self-latching) flush bolts on the inactive leaf. Automatic flush bolts engage when the inactive leaf closes, ensuring positive latching without relying on manual action. Manual flush bolts are generally not permitted on fire-rated pairs because there is no guarantee they will be engaged during a fire event. The flush bolts must be UL listed for the specific fire rating of the assembly.
What is the difference between an astragal and a mullion?
An astragal is attached to one of the door leaves (typically the inactive leaf) and overlaps the gap between the two meeting stiles when both doors are closed. It moves with the door. A mullion is a fixed vertical member anchored to the frame head and floor, dividing the opening into two separate single-door openings. Astragals are standard on most commercial pairs and are required on nearly all fire-rated pairs. Mullions are used when a fixed center post is acceptable.
What are the fire rating levels available for double door assemblies?
Double door assemblies are available at five fire rating levels: 20-minute, 45-minute, 60-minute, 90-minute, and 3-hour (180-minute). The required rating is determined by the fire rating of the wall assembly the doors are installed in. All components of the pair (doors, frame, hinges, closers, exit devices, astragal, flush bolts, coordinator, and glazing) must be listed and labeled at or above the required rating. The entire assembly is rated to its lowest-rated component.
How do I determine the handing of a double door opening?
Stand on the outside of the opening (the key side, pull side, or corridor/public side). The hand is determined by the active leaf. If the active leaf hinges are on the right, it is a right-hand pair. If on the left, it is a left-hand pair. If the door swings toward you (push side becomes the outside), add "reverse" to the designation (RHR or LHR). The inactive leaf handing is always opposite the active leaf.
What happens if the astragal is missing on a fire-rated pair?
A fire-rated pair without an astragal will fail fire inspection. The gap between the meeting stiles allows smoke and flame passage, compromising the fire barrier. NFPA 80 requires that the gap between meeting stiles on fire-rated pairs be protected by a listed overlapping astragal. Adding an astragal after installation is possible but requires field modification that may not match factory preparation quality. Specify the astragal during the ordering process to avoid this issue.