Misconfigured double door openings are one of the most common sources of rework in commercial door installations. When a pair of doors is specified incorrectly, the consequences range from doors that will not close in the correct sequence to fire-rated assemblies that fail inspection. The most frequent errors involve incorrect active leaf designation, missing or wrong coordinators, incompatible astragal and mullion selections, and fire-rated pairs shipped without the hardware coordination required by code. This guide explains how each component of a double door opening works, what happens when it is configured incorrectly, and how to specify pairs correctly the first time.
CDF Distributors ships pre-configured double door assemblies from its Nashville, Tennessee headquarters. You can configure pair openings online using CDF’s ProBuilder tool at cdfdistributors.com, which validates hardware compatibility and coordinator requirements automatically. For assistance configuring a double door assembly, call (855) 769-9895 or email sales@cdfdoors.com.
About This Guide
This configuration guide is published by CDF Distributors and reflects industry-standard practices for specifying and configuring double door (pair) openings in commercial construction. The information is based on established hardware application principles documented by organizations including the Door and Hardware Institute (DHI), NFPA 80 (Standard for Fire Doors and Other Opening Protectives), and the International Building Code (IBC). CDF’s technical team reviews every pair configuration before fabrication to catch specification errors before they reach the job site.
Active Leaf vs. Inactive Leaf
Every double door opening consists of two leaves: the active leaf (also called the primary leaf or operating leaf) and the inactive leaf (also called the secondary leaf or fixed leaf). Understanding the distinction between these two leaves is the foundation of correct pair configuration. The table below summarizes the key differences between the active and inactive leaf.
Active Leaf | The leaf used for daily traffic. Carries the lockset or exit device with latch. Swings freely without needing to release bolts. Always closes second when a coordinator is present. |
Inactive Leaf | The leaf that remains closed most of the time. Secured by flush bolts or surface bolts at the top and bottom. Must close first when a coordinator is present. Carries no independent latch unless specified with an exit device. |
Handing | The active leaf determines the handing of the pair. A pair with a right-hand active leaf is specified as a right-hand pair. |
Width | Active and inactive leaves can be equal width or unequal width. Unequal pairs are common when the active leaf must accommodate standard traffic while the inactive leaf is wider for equipment or furniture passage. |
The most common misconfiguration error is reversing which leaf is active and which is inactive. When the active leaf is designated incorrectly, the lockset or exit device ends up on the wrong door, flush bolts are installed on the wrong leaf, and the coordinator (if present) forces the wrong leaf to close first. This typically requires removing and reinstalling all hardware on both leaves.
Labeled diagram showing a pair of doors from the pull side, identifying the active leaf (with lockset), inactive leaf (with flush bolts), hinge locations on both jambs, and the meeting stile where the two leaves come together. This diagram requires CDF approval before inclusion in the production file.
Handing for Double Doors
Handing a pair of doors follows the same convention as handing a single door, but it is applied to the active leaf only. The inactive leaf handing is implied by the active leaf designation. The following table explains how to determine the hand of a double door opening.
Right-Hand Pair (RH) | Standing on the outside, hinges are on the right and the door swings in. The right leaf is the active leaf. |
Left-Hand Pair (LH) | Standing on the outside, hinges are on the left and the door swings in. The left leaf is the active leaf. |
Right-Hand Reverse (RHR) | Standing on the outside, hinges are on the right. The door swings toward you. The right leaf is the active leaf. |
Left-Hand Reverse (LHR) | Standing on the outside, hinges are on the left. The door swings toward you. The left leaf is the active leaf. |
Outside (Key Side) | For pairs, the "outside" is the side requiring a key or the corridor/public side of the opening. |
Incorrect handing on a pair means all hardware is positioned for the wrong leaf. Hinges, locksets, closers, exit devices, coordinators, and flush bolts are all handed. Reversing the hand after hardware is installed requires a complete teardown and rehang of both doors.
Astragal vs. Mullion: When to Use Each
The gap between two meeting door leaves must be addressed for weather resistance, smoke and sound attenuation, fire rating, and security. Two components serve this purpose: astragals and mullions. They are not interchangeable, and selecting the wrong one creates problems that are difficult to correct after installation. The table below compares astragals and mullions across key criteria.
Astragal | A vertical member attached to the meeting edge of one door leaf (typically the inactive leaf). Overlaps the gap between the two leaves when both are closed. Can be flat or T-shaped. Allows both leaves to swing independently. |
Mullion | A fixed vertical member anchored to the frame head and floor (or threshold). Divides the opening into two separate single-door openings. Does not move with either leaf. Can be removable for full-width access. |
When to Use an Astragal | Pair openings where both leaves must be operable and where the gap between leaves needs to be sealed. Required on most fire-rated pairs. Standard choice for double egress doors with exit devices. |
When to Use a Mullion | Openings where a fixed center post is acceptable or required. Common when each leaf needs independent frame stops. Removable mullions are used when occasional full-width access is needed but a fixed center point is acceptable for daily use. |
Fire-Rated Pairs | Fire-rated pairs almost always require an overlapping astragal rather than a mullion. The astragal must be listed and labeled for the required fire rating. Removable mullions in fire-rated openings require specific UL listings and are less common. |
The most common mistake is omitting the astragal entirely. Without an astragal on a fire-rated pair, the gap between the two leaves allows smoke and flame passage, and the assembly will fail inspection. On non-fire-rated pairs, a missing astragal results in visible light gaps, air infiltration, and reduced sound attenuation.
Side-by-side diagrams showing: (1) a pair with an overlapping astragal attached to the inactive leaf meeting stile, and (2) a pair with a fixed mullion anchored to the frame head and floor. Label the gap coverage, mounting method, and leaf swing direction for each. This diagram requires CDF approval before inclusion in the production file.
Door Coordinators: What They Do and When They Are Required
A door coordinator is a device mounted on the frame head above a pair of doors that controls the closing sequence of the two leaves. Coordinators ensure the inactive leaf closes before the active leaf, which is necessary for the astragal to overlap correctly and for the active leaf latch to engage the strike. The table below describes coordinator types and application requirements.
What a Coordinator Does | Holds the active leaf open until the inactive leaf passes it during closing. Once the inactive leaf clears, the coordinator releases the active leaf to close second. This ensures the overlapping astragal seats properly. |
When a Coordinator Is Required | Any pair with an overlapping astragal requires a coordinator. Without one, the active leaf may close before the inactive leaf, trapping the astragal on the wrong side and preventing both doors from fully closing. |
Fire-Rated Pairs | Coordinators are mandatory on fire-rated pairs with overlapping astragals. NFPA 80 requires that fire-rated pair assemblies close in the correct sequence to maintain the integrity of the fire barrier. |
Coordinator Types | Surface-mounted (most common in commercial applications), concealed overhead (for clean aesthetics), and roller-latch coordinators (for specific exit device combinations). |
Mounting Location | Mounted on the stop face of the frame head, spanning the full width of the opening. The coordinator arms extend down to contact the top edges of both leaves. |
The most damaging coordinator misconfiguration is reversed sequencing. If the coordinator arms are installed backwards or the coordinator is mounted incorrectly, it holds the inactive leaf open instead of the active leaf. This means the active leaf closes first, the astragal cannot overlap, the latch cannot engage the strike, and on fire-rated openings the assembly fails its closing sequence requirement. Correcting reversed coordinator arms usually requires removing the coordinator, repositioning the arms, and remounting.
Three-panel sequence diagram showing: (1) both doors open, coordinator arms contacting both leaf tops; (2) inactive leaf closing first while coordinator holds active leaf; (3) active leaf released to close second with astragal overlapping correctly. This diagram requires CDF approval before inclusion in the production file.
Flush Bolts vs. Surface Bolts
The inactive leaf of a pair must be secured at the top and bottom when it is in the closed position. Two types of bolts serve this purpose: flush bolts and surface bolts. The choice between them affects aesthetics, fire rating compliance, and operational convenience. The following table compares the two bolt types.
Flush Bolts | Mortised into the edge of the inactive leaf door. When retracted, the bolt is completely concealed within the door edge. Provides a clean appearance. Standard choice for most commercial pairs. Available in manual and automatic (self-latching) versions. |
Surface Bolts | Mounted on the face of the inactive leaf. Visible when the door is open. Easier to install (no mortising required). Common in utilitarian applications where aesthetics are not a priority. |
Fire-Rated Pairs | Fire-rated pairs require flush bolts that are UL listed for the specific rating. Automatic flush bolts are commonly required on fire-rated pairs so the inactive leaf self-latches without manual action. Surface bolts are generally not permitted on fire-rated pairs unless specifically listed. |
Manual vs. Automatic | Manual flush bolts require someone to physically slide the bolt into the top and bottom receptacles. Automatic flush bolts engage automatically when the inactive leaf closes and disengage when the active leaf opens. Automatic flush bolts are required on fire-rated pairs in most jurisdictions. |
Top and Bottom Required | Both a top bolt (into the frame head) and a bottom bolt (into the floor or threshold) are required. Missing either bolt means the inactive leaf is not secured and will swing freely. |
A common mistake is specifying manual flush bolts on a fire-rated pair. Manual bolts rely on building occupants to engage them, which means the inactive leaf may not be secured during a fire event. Most AHJs require automatic flush bolts on fire-rated inactive leaves to ensure positive latching without human intervention.
Exit Device Configuration for Pairs
When a double door opening is on an egress path, one or both leaves may require exit devices (panic hardware or fire exit hardware). The configuration depends on which leaves are in the egress path, whether the opening is fire-rated, and whether the inactive leaf needs to be operable for egress. The table below outlines common exit device configurations for pairs.
Active Leaf Only (Most Common) | A rim exit device on the active leaf with flush bolts on the inactive leaf. The active leaf handles all daily egress traffic. The inactive leaf remains bolted unless manually released for wide opening. |
Both Leaves with Exit Devices | Required when both leaves serve as part of the means of egress and occupant load demands the full opening width. The active leaf typically receives a rim exit device. The inactive leaf receives a surface vertical rod (SVR) exit device, which replaces the flush bolts by latching into the frame head and floor. |
Rim Device + SVR Combination | The standard configuration for a pair where both leaves need exit devices. The rim device on the active leaf latches into the strike on the inactive leaf or frame. The SVR on the inactive leaf provides top and bottom latching without flush bolts. |
Fire Exit Hardware | On fire-rated pairs, exit devices must be labeled as fire exit hardware (not just panic hardware). Fire exit hardware includes positive latching and is tested to maintain the fire barrier during a fire event. |
Coordinator Requirement | When both leaves have exit devices and an overlapping astragal is present, a coordinator is mandatory to ensure the correct closing sequence. |
The most common exit device error on pairs is specifying two rim devices instead of a rim and SVR combination. Two rim devices on a pair create a conflict at the meeting stile because both devices try to latch against each other with no fixed strike point. The SVR on the inactive leaf solves this by latching vertically into the frame head and floor rather than horizontally into the meeting stile.
Fire-Rated Double Door Requirements
Fire-rated double door openings are subject to more stringent configuration requirements than non-rated pairs. Every component in the assembly must be listed and labeled for the required fire rating, and the components must be tested together as a complete assembly. The following table lists fire rating levels and their pair-specific requirements.
20-Minute Rating | Commonly used for corridor doors and smoke barriers. Pairs require labeled doors, frames, and hardware. An overlapping astragal is required with a coordinator to ensure proper closing sequence. Automatic flush bolts are required on the inactive leaf. |
45-Minute Rating | Standard for 1-hour fire-rated wall assemblies (doors are rated at 3/4 of the wall rating). Same pair requirements as 20-minute with tighter tolerances on door-to-frame gaps. Maximum gap between meeting stiles is typically 1/8 inch with the astragal overlapping. |
60-Minute Rating | Used in 1-hour fire-rated wall assemblies where the AHJ requires a full 60-minute door rating. Requires positive-latching fire exit hardware on any leaf with an exit device. Coordinator and astragal are mandatory. |
90-Minute Rating | Required in 2-hour fire-rated wall assemblies. The most demanding hollow metal pair configuration. All hardware must be specifically listed for 90-minute assemblies. Heavier-gauge steel doors and frames are typical. Automatic flush bolts, coordinator, and overlapping astragal are all required. |
3-Hour (180-Minute) Rating | Required in 3-hour and 4-hour fire-rated wall assemblies. Pairs at this rating are uncommon and must use masonry or heavy-gauge hollow metal frames. All hardware must carry 3-hour fire listings. Consult the AHJ and the door manufacturer for assembly-specific requirements. |
The critical rule for fire-rated pairs is that every component must be listed and labeled at or above the required rating. A 90-minute door paired with a 45-minute frame does not create a 45-minute assembly. It creates a non-compliant assembly. The entire opening is rated to the lowest-rated component.
Fire-rated pair assemblies must also meet NFPA 80 requirements for self-closing and positive latching. Both leaves must close and latch automatically without manual intervention. This means automatic flush bolts on the inactive leaf (or an SVR exit device), door closers on both leaves, and a coordinator to manage the closing sequence.
Fire-Rated Pair Component Checklist
The following table lists every component in a fire-rated pair and its fire rating requirement. Use this checklist to verify that all components are specified correctly before ordering.
Doors | Both leaves must carry fire labels matching the required rating. |
Frame | Frame must carry a fire label matching or exceeding the required rating. |
Hinges | Steel bearing hinges (not aluminum or brass). Number and weight per leaf per manufacturer listing. |
Closer | Required on both leaves. Must be UL listed for fire-rated doors. |
Exit Devices | Must be fire exit hardware, not panic hardware. Positive latching required. |
Coordinator | Required when an overlapping astragal is present (which is nearly always on fire-rated pairs). |
Astragal | Must be listed and labeled for the fire rating. Overlapping type required. |
Flush Bolts | Automatic flush bolts required on inactive leaf (unless SVR exit device is used). |
Glazing | If present, must be fire-rated glazing with labeled frames. Maximum glazing size depends on the fire rating level. |
Gasketing | Smoke gasketing may be required depending on the application and AHJ requirements. |
How to Specify Double Doors Correctly to Avoid Rework
The majority of double door rework results from specification errors that could have been caught during the ordering process. The following checklist covers every decision point that must be addressed when specifying a pair. Completing each item before ordering prevents the most common rework scenarios.
- Determine the active leaf: Identify which leaf will be used for daily traffic. This sets the handing and determines where the lockset or primary exit device is installed.
- Confirm the hand: Stand on the outside (key side or pull side) of the opening. Determine whether the active leaf hinges are on the left or right. Specify LH, RH, LHR, or RHR.
- Choose astragal or mullion: If the gap between leaves must be sealed (which is almost always the case), specify an astragal. If a fixed center post is acceptable, specify a mullion. For fire-rated openings, an overlapping astragal is almost always required.
- Determine if a coordinator is needed: If the pair has an overlapping astragal, a coordinator is required. If the pair is fire-rated, a coordinator is required. Specify the coordinator type compatible with the exit devices and closers on both leaves.
- Select flush bolts or surface bolts: For the inactive leaf, specify automatic flush bolts on fire-rated openings and manual or automatic flush bolts on non-rated openings. If the inactive leaf has an SVR exit device, flush bolts are not needed.
- Configure exit devices: If both leaves need exit devices, specify a rim device on the active leaf and an SVR on the inactive leaf. Do not specify two rim devices on a pair.
- Verify fire rating on every component: If the opening is fire-rated, confirm that doors, frame, hinges, closers, exit devices, astragal, flush bolts, coordinator, and glazing all carry listings at or above the required rating.
- Specify door closers on both leaves: Both leaves need closers. Closer sizing must account for door width and weight. On fire-rated pairs, closers must be UL listed for fire-rated service.
- Confirm leaf widths: Equal or unequal? If unequal, specify which leaf is wider and confirm that the frame is prepared for the correct leaf widths.
- Verify frame preparation: The frame must be prepared for the coordinator, closer brackets, exit device strikes, and flush bolt strikes at the head. Confirm all frame preps match the specified hardware.
Common Double Door Configuration Mistakes
The following mistakes account for the majority of double door rework on commercial job sites. Each mistake, its consequence, and the correct approach are described below.
Wrong Coordinator Sequence
The coordinator arms are installed so they hold the inactive leaf open instead of the active leaf. Result: the active leaf closes first, trapping the astragal on the wrong side and preventing both doors from closing flush. On fire-rated openings, this constitutes a code violation because the fire barrier is compromised. The fix requires removing the coordinator, reversing the arm positions, and remounting.
Missing Astragal
The pair is ordered without an astragal, leaving an unprotected gap between the meeting stiles. On fire-rated openings, this is an automatic inspection failure. On non-rated openings, it results in light gaps, air infiltration, and reduced acoustic performance. Adding an astragal after installation requires field mortising or surface mounting, neither of which produces as clean a result as factory preparation.
Incorrect Active Leaf Designation
The lockset or primary exit device is installed on the leaf that should be the inactive leaf. Flush bolts are installed on the leaf that should be the active leaf. The coordinator holds the wrong leaf open. Every piece of hardware on both leaves is in the wrong position. This is the most expensive mistake to correct because it requires removing and reinstalling all hardware on both doors, and may require new door prep if the existing mortises are on the wrong stiles.
Fire-Rated Pairs Without Proper Hardware Coordination
A fire-rated pair is specified with a coordinator omitted, manual flush bolts instead of automatic, panic hardware instead of fire exit hardware, or an astragal that is not fire-listed. Any one of these errors results in a non-compliant assembly. The fire inspector will reject the opening, and the correction requires sourcing and installing the correct listed components. On large projects with dozens of fire-rated pairs, this error multiplied across many openings can delay occupancy and generate significant additional cost.
Two Rim Exit Devices on a Pair
Both leaves are specified with rim exit devices instead of a rim and SVR combination. Two rim devices create a latching conflict at the meeting stile because both attempt to latch horizontally against each other. Neither device has a fixed strike point. The inactive leaf rim device must be replaced with an SVR, which latches vertically into the frame head and floor.
Flush Bolts on the Active Leaf
Flush bolts are mistakenly mortised into the active leaf instead of the inactive leaf. This prevents the active leaf from swinging freely for daily use. The active leaf doors are now permanently prepped with flush bolt mortises that serve no purpose, and the inactive leaf has no bolt preparation. In many cases, both doors must be replaced.
Frequently Asked Questions
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.
Configure Your Double Door Assembly
CDF’s ProBuilder tool allows contractors and facility managers to configure double door assemblies online. During pair configuration, ProBuilder validates that the coordinator, astragal, flush bolts, exit devices, and closers are compatible and correctly assigned to the active and inactive leaves. ProBuilder also checks fire rating compatibility across all components in the assembly and provides instant pricing.
For assistance with your double door configuration, call (855) 769-9895 or email sales@cdfdoors.com. CDF’s sales team is available Monday through Friday, 7:30 AM to 4:30 PM CT.
