Field note
Insulated metal panels in the wall-and-ceiling number
Insulated metal panels (IMPs) are a factory sandwich: two metal skins and a foam or mineral-wool core, tongue-and-groove, hung as cladding or as a wall. They are not gypsum, not exterior sheathing on CFS, and not a metal-stud partition with batt. Some commercial wall-and-ceiling shops sell them. Many do not. The directory term is insulated metal panels.
This page is for the drywall / W&C estimator who has to decide whether the IMP line is in the number, and how gypsum dies into a panel wall when it is. It is not a panel-mill catalog and not a substitute for the manufacturer’s installation manual, FM / UL listings, and the envelope drawings.
What the product class is
Horizontal or vertical IMP, concealed- or exposed-fastener, interior liner panel or exterior architectural panel. Thickness and joint are mill details. Foam cores (polyiso and related plastics) bring IBC Chapter 26 plastics / thermal-barrier language into the room; mineral-wool cores show up where the spec wants noncombustible fill. Flame-spread, fire-tested wall assemblies, and approval listings (the FM 4880-class conversation, ASTM E84 on components, any ASTM E119 assembly the mill actually has) live on the panel submittal, not on a gypsum GA-600 page.
Do not treat an IMP as a silent substitute for a Type X partition or for glass-mat sheathing on exterior CFS. Different skin, different joint, different listing, different crew skill.
Interior liner panels in food, cold-storage, and some industrial rooms are still IMPs. They are not washable gypsum and not FRP glued to Type X. If the room spec named a panel, the takeoff is panel.
Who owns the install
Three common splits. Read the invitation. Do not assume.
Drywall / W&C shop owns IMP. The same company that sells metal stud, board, and sometimes ACT also hangs panels — usually because the shop already does exterior CFS, architectural metals, or industrial interiors. Then the estimate still splits: panel labor and trim are not a gypsum hang rate, and the mill’s certified-installer rule, if any, is a bid condition. Directory: Insulated metal panels.
Separate panel installer. GC buys IMP from a mill-network installer. The drywall sub meets the panel at every interior partition, soffit, and ceiling. That meeting is your detailing problem even when the panel is not in your contract.
GC or envelope package. Panels ride with skin / roofing. Same coordination. Write the exclusion: IMP furnish and install by others; gypsum transitions to IMP included only where shown.
Residential production shops almost never own IMP. A townhouse with a panel accent is still a commercial-adjacent envelope, not a production hang. Keep those crews off the elevation unless the shop actually sells the system.
Detailing next to gypsum
This is where W&C work actually touches the panel.
Interior partitions that die into IMP. Metal-stud track does not bite a foam core like it bites a deck. You need a mill-accepted attachment: a hat channel or furring on the interior skin, a secondary stud wall inboard, or a clip the panel manufacturer drew. Powder-actuated pins into the interior face are not a generic drywall habit. Seal the partition perimeter to the panel — STC and smoke both care — with the sealant class the two specs allow.
Fire. A listed gypsum fire partition or fire barrier that butts an IMP is two assemblies meeting. The IMP’s own fire listing does not make the gypsum wall listed, and gypsum layers on the panel interior do not make the IMP a GA-600 design. Head-of-wall and through-penetration firestop at that joint are tested details or an engineered judgment the documents have to name. Do not foam the joint and call it a 1-hour close.
Thermal and vapor. A gypsum partition that punches through an insulated panel wall is a thermal bridge if the cavity is open to the exterior skin. The envelope consultant owns the concept; the drywall sub owns not cutting a random hole for a soffit. Closures, backer, and spray-foam infill at panel cutouts are often in the panel number. Qualify them.
Ceilings. ACT wall angle on an IMP skin needs a substrate the angle can fasten to — the interior face, a closure, or a gypsum bulkhead. Gypsum lids and soffits that return to panel need a bead and a seal, not a smeared butt. Drywall-suspension hangers do not shoot into foam.
Openings. Doors, lites, and louvers in an IMP wall are panel-mill details (framed cutouts, flashing, integral frames). Wrapping those openings with gypsum as if they were hollow-metal in a stud wall is the wrong system. If DFH is in your package and the wall is IMP, stop and read which trade furnishes the framed opening.
Movement. Panels run long. Gypsum wants control joints. Do not hard-tape a gypsum return across a panel joint and expect both products to move.
Bid notes
If IMP is yours:
- Panel type, thickness, orientation, finish, and trim from the mill on the submittal — not a generic “insulated panel” allowance
- Substrate and alignment (structure, CFS backup, or self-spanning panel as drawn)
- Openings, flashings, closures, sealants, and field cuts
- Lift, staging, and weather — this is envelope work
- Any mill training / certified-installer requirement
- Interior gypsum, stud, and ACT as separate lines that meet the panel
If IMP is not yours:
- Exclude furnish and install
- Include only the gypsum / stud / ACT transitions that are shown
- RFI attachment method of interior partitions to the interior skin
- Do not donate panel trim or color-matched closures from the drywall trailer
No invented production rates. Panel hang is not 5/8 on 24-inch studs.
Commercial vs residential
Commercial W&C. IMP is a real advertised scope on some shops and absent on most. Map it from the company website when you index a contractor — do not guess a shop into insulated metal panels. Coordination with gypsum is on almost every industrial and mixed-envelope job whether you hang the panel or not.
Residential production. Not this product. Metal panel on a house is usually a siding sub. Do not send a tape crew to lay out IMP joints.
Related directory
Panel scope: Insulated metal panels. Interior steel that meets it: Steel stud / framing. Exterior backup when the skin is not IMP: Exterior cold-formed framing. Ceilings that die into panel: Acoustical ceilings (ACT). Board that is not a panel: choosing drywall type.
FAQ
Is IMP part of a typical drywall subcontract?
Only when the bid and the shop say so. Interior metal stud and board usually are. IMP is a separate question on every invitation.
Can I hang gypsum directly to the interior skin of an IMP?
Only with a method the panel mill and the gypsum application standard both accept. Foam core is not a stud flange. See how to hang drywall for gypsum rules; the panel manual for the skin.
Does a fire-rated IMP wall replace a listed gypsum corridor?
No. Different listings. Build each assembly as specified and detail the joint.
Who owns sealant at the gypsum-to-panel joint?
Write it. Envelope sealant, firestop, and interior acoustical caulk are three different tubes. The partition sub often owns the interior bead; do not assume the panel installer owns it.