The Opening Without a Door Still Needs a Frame
Not every opening in a building gets a door. Corridor pass-throughs, open archways in office suites, interior retail alcoves, and wide passages in healthcare facilities often call for a finished frame with no leaf installed. This article explains what cased open frames are, where they belong in a hardware schedule, and what decisions a contractor or specifier needs to make before ordering. It is aimed at commercial subs writing schedules, facility planners laying out interior partitions, and architects trying to keep the opening list clean and complete.
What Is a Cased Open Frame?
A cased open frame is a hollow metal frame manufactured without a rabbet stop -- the integral projection that a door leaf closes against. Because there is no door to stop, the frame profile is open and flush through the throat of the opening. The result is a clean, finished border around the rough opening that protects the wall edge, carries the load of the surrounding partition, and provides a uniform appearance without any hardware or door leaf.
In hollow metal frame terminology, this profile is sometimes called a cased opening frame, a double-egress style opening without leaves, or simply an open section frame. It is distinct from a single-rabbet or double-rabbet frame, which are designed to receive one or two door leaves respectively.
Where Cased Open Frames Are Commonly Specified
- Healthcare corridors: Wide pass-throughs between nursing wings or between a clean utility room and a corridor, where traffic flow must be unobstructed but the wall edge still needs steel protection.
- K-12 schools: Open connections between a library and a reading room, or between a cafeteria servery and the dining area, where no door is required but the opening still needs a durable, paintable frame to survive custodial equipment and cart traffic.
- Retail and hospitality: Archways between selling floors or back-of-house pass-throughs where aesthetics matter and the frame finishes the drywall edge cleanly.
- Industrial and warehouse facilities: Openings in partition walls that separate areas but do not require controlled access -- pedestrian pass-throughs in light manufacturing or break room entries.
- Office interiors: Open suite entries and reception area openings where the design intent is an unobstructed threshold but the hollow metal frame gives the opening visual weight and physical durability.
Key Ordering Decisions Before the Frame Ships
A cased open frame looks simple on a schedule line, but several decisions must be made before the order goes to the mill. Getting these right prevents field problems and return freight.
1. Frame Profile and Jamb Depth
The jamb depth must match the partition thickness. A cased open frame ordered for a 3-1/2 inch stud wall will not fit cleanly in a 6-inch masonry wall. Confirm the wall assembly -- drywall stud, masonry, or plaster -- and order the matching profile. Hollow metal frames are manufactured in drywall (slip-on) profiles and masonry profiles; both are available in cased open configurations.
As the knowledge base notes, the face dimension of the frame -- the area parallel to the wall surface -- affects how the frame reads visually and how anchors engage the surrounding partition material. A wider face reads heavier and is often preferred in institutional settings for durability and appearance.
2. Frame Gauge
Hollow metal frames are commonly available in 14, 16, and 18 gauge cold-rolled steel. Lighter gauge (18) is acceptable in low-traffic interior locations. High-traffic corridors in schools or hospitals typically warrant 16 gauge or heavier. The opening may not have a door, but it will still take cart impacts, wheelchair traffic, and daily abuse in active facilities.
3. Anchoring Method
The frame must be anchored to the surrounding structure. Options include:
- Masonry T-anchors or wire anchors for masonry walls
- Stud anchors or snap-in anchors for drywall and metal stud construction
- Floor anchors at the base of the jambs for additional stability in heavy-traffic openings
Confirm the anchor type with the frame manufacturer before ordering. Field fabricating anchors on a cased open frame is possible but adds labor cost and delays.
4. Hardware Preparations -- or the Lack Thereof
Because no door is planned, cased open frames typically ship without hinge reinforcements, strike preparations, or closer reinforcements. However, if there is any chance the opening will receive a door in the future -- a common scenario in phased construction or tenant improvement projects -- ordering the frame with standard hardware preps costs very little at the mill and avoids a costly field modification later.
This is worth a conversation with the architect or owner before the schedule is finalized. Retrofitting hinge and strike preparations into an installed hollow metal frame is possible but requires welding and grinding that is difficult to do cleanly in the field.
5. Finish and Paint
Cased open frames are typically supplied with a factory primer coat and painted in the field to match the wall. Stainless steel and galvanized options are available for exterior-adjacent or high-humidity applications such as pool areas or exterior covered walkways. Specify the finish condition at time of order.
Cased Open Frames and the Hardware Schedule
On a hardware schedule, cased open frames appear as a distinct hardware set with no lock, no closer, no hinges, and no exit device. The set line should still be called out explicitly so the frame does not get confused with a door opening that simply had its hardware group omitted by mistake. A clear notation -- for example, "Hardware Set CO-1: Cased Open Frame, No Door, No Hardware" -- prevents shop drawing rejections and field questions.
If the opening is wide enough to qualify as an accessible route, verify that the clear width meets the applicable accessibility standard for the occupancy type. A cased open frame that is too narrow may need to be reworked before the wall is built -- not after.
What DoorwaysPlus Can Help You Specify
DoorwaysPlus stocks and sources hollow metal frames from established manufacturers across a range of profiles, gauges, and anchor configurations. Whether you need a standard cased open section for a single interior partition or a series of wide-throat frames for a healthcare renovation, our team can help you confirm the profile, gauge, and anchoring details before the order ships -- so the frame fits the opening and the schedule stays on track.
Have a project with mixed openings -- some with doors, some without? We can help you build a complete schedule that covers both. Contact DoorwaysPlus at DoorwaysPlus.com or reach out to our commercial sales team for frame specifications and lead time information.