Metal Wall Panel Systems

A panel system is the construction, attachment, and joint design that turn sheet metal into a wall. The same aluminum coil can become a flat cassette, a corrugated profile, a composite panel, or a perforated screen, with different performance, cost, and appearance. This hub is the format layer of the metal wall coverings guide.

First name the job	Open the relevant explanation
Drain	Outer skin, cavity and backup wall
Enclose	Insulating panel and its joints
Screen	Open screen and wall behind it

The Whole Building Design Guide’s metal panel wall systems note is the right frame: the system includes openings, flashings and the backup, not only the visible sheet.

Three jobs systems actually do

Most arguments get clearer if you name the job first.

Drain. Metal rainscreen cladding puts an outer metal layer over a cavity that weeps and dries. Cassette panels and many Metal Composite Material panels are hung this way. Face-sealed metal on a large weather wall is the usual way this job is skipped.

Enclose. Insulated metal panels combine two metal faces and an insulating core, while our insulated metal wall panels R-value, butyl joint, and span guide details PIR, hybrid QuadCore, and mineral wool core specifications. Thermal and fire numbers belong to that tested sandwich. Copying those numbers onto a single-skin rainscreen is a specification error.

Screen. Perforated metal panels, our quantitative perforated metal facade panels open area, wind, and specification guide, and expanded metal mesh facades filter light, views and equipment. They are not a weather barrier by themselves.

For interior reverberation control in lobbies, offices and corridors, see commercial acoustic metal wall panels.

The system families

Single-skin metal panels are one formed sheet, fastened exposed or concealed. They are the simplest and usually the most economical. Flatness, gauge and joint weather are the design load.

Metal Composite Material panels are two thin metal skins bonded to a core. The Metal Construction Association defines that family here: Metal Composite Material. Flatness is the reason they exist. Fire language follows the core and the listed assembly, not the aluminum face. This site writes the full term in titles and anchors. If a drawing only says MCM, open what MCM means in cladding.

Insulated metal panels are cladding and insulation in one shop-built module. They appear on logistics, education and some commercial backups. They are a poor default for a high-design cassette rainscreen unless the project actually wants that enclosure type.

Rainscreen cladding is the dominant modern facade approach for architectural metal. The cavity, not the paint, is what keeps the backup dry.

Corrugated and profiled panels add stiffness and hide oil canning at low cost. They are the wrong expectation if the rendering shows a perfectly flat dark cassette.

For a folded-sheet elevation with raised joints, standing seam wall panels explain how concealed sliding clips, fixed zones and termination clearances accommodate thermal movement.

Cassette panels are folded trays with concealed fixings and shadow-line joints. Custom corners and mixed modules are where cost and tolerance problems appear.

Perforated and expanded metal are openness systems. Specify free area, attachment and the weather plane behind them.

Types of metal wall panels compared

Read the names on three levels: material construction (single-skin, MCM or IMP), panel shape (flat, profiled or cassette), and drainage method (such as a rainscreen). A cassette can be single-skin; a rainscreen can use several panel constructions. Use this table when a drawing, quote or product sheet names a panel type and you need to know what is actually being offered. Each row is summarised from the system guide linked in the first column; open that guide before copying any number. Sizes, gauges and prices are not compared here, because they belong to a specific product.

Type	How it is built	Names you may also see	Where it usually goes
Single-skin	One metal thickness: flat sheet, brake-formed metal, roll-formed profile or heavier plate. No bonded core	Flat sheet, plate, brake metal	Exterior skins over a backup wall; interior feature walls
Metal Composite Material	Two thin metal skins bonded to a core a few millimetres thick, routed and folded into trays	MCM; ACM when the skins are aluminum	Flat exterior facades, usually as a rainscreen skin
Insulated metal panel	Two metal skins bonded to an insulating core, with interlocking side joints	IMP, sandwich panel	Cold storage, industrial and long commercial walls
Cassette	A folded tray with returned edges, hung on concealed clips or rails	Folded tray panel	Architectural rainscreens where the joint grid is part of the design
Rainscreen	Not a panel type: a drained, usually ventilated cavity and continuous barrier behind any of the skins above	Rainscreen cladding	Exterior walls
Corrugated and profiled	Roll-formed sheet with a repeating wave or trapezoidal rib, mostly face-fastened	Trapezoidal rib panel, box rib	Exterior walls where texture, speed and cost matter more than a flat plane
Standing seam	Folded sheet edges form raised seams over concealed clips, with movement provisions defined by the wall system	Angled standing seam, standing seam wall panels	Exterior skins with expressed seam lines and detailed terminations
Perforated	Sheet with punched or laser-cut openings	Perforated screen, laser-cut decorative panel	Screens and sunshades in front of a real wall; interior liners
Expanded mesh	Sheet slit and stretched into a mesh	Expanded metal facade	Screens in front of a real wall

Two cautions apply to the names. A trade name or abbreviation tells you the family, not the core, coating or fire listing; read those from the product’s own data. And the same letters can mean different things: if a drawing only says MCM, check what MCM means in cladding.

Flat panels versus ribbed and corrugated profiles

A flat panel has to get its stiffness from somewhere other than shape: heavier gauge, folded returns, back stiffeners, smaller modules, or a bonded core. That is why dead-flat walls are usually cassettes, Metal Composite Material or plate, and why flat single-skin sheet needs oil canning to be designed for. A ribbed or corrugated profile gets stiffness from rib depth, so a thinner sheet can span farther, and its shadow pattern hides waviness that a flat sheet would show.

Choose flat when the elevation is meant to read as a smooth plane with a visible joint grid, and budget for the stiffening or core that keeps it flat. Choose profiled when coverage, speed and cost lead, and the design accepts texture and, on the standard version, a visible fastener line. If a rendering shows a dark, glossy, perfectly flat wall but the budget is set for profiled sheet, resolve that conflict before you pick a product.

Metal wall panels versus metal shingles

Metal shingles are small interlocking flat pieces, such as the flatlock shingles described in the zinc wall cladding guide and the flat-seam shingles in the copper wall cladding guide. Small modules and many folds make them stiff and let them wrap curves, but they take a lot of skilled labour and usually run over continuous sheathing. The panel systems on this hub use larger modules on clips, rails or girts. If a product is sold as a metal shingle, confirm that its maker lists it for walls and not only for roofs. For flat-lock wall panels specifically, the flat-lock metal panels guide compares the backing, clip and layout conditions that named manufacturers state.

Attachment is part of the system

Exposed fasteners are honest and economical on profiles. Concealed clips are the architectural default on cassettes and many composite trays. The fastener metal must be compatible with the face metal; that is a corrosion note, not a hardware afterthought. Installation sequencing decides whether the drawn joint is the built joint.

What not to copy between families

An insulated-panel span table does not apply to 3 mm aluminum plate. A composite fire listing does not apply to solid sheet, and the reverse is also false. A perforated screen does not keep out wind-driven rain the way a shiplap profile does. None of these systems make metal panels fireproof; see metal wall panel fire performance.

How to use this hub

1. Name drain, enclose or screen.
2. Open the one system guide that matches that job.
3. Pick the metal on the materials hub.
4. Place the wall on the applications hub.
5. Write finish, movement and listings on the design and specification hub.