Metal Wall Coverings: Panels, Cladding, Systems

Choosing a colour before drainage and attachment can force a specification rewrite. Decide use → system → metal → finish → details; use this map to open the guide for the unresolved step.

Step	Record first	Cost of skipping it
Use	Interior or exterior, building and exposure	Wrong application requirements
System	Drainage, insulation and attachment	An incompatible wall build-up
Metal	Alloy, thickness and coating	Unverified load or corrosion assumptions
Finish	Appearance and maintenance terms	A finish the owner cannot maintain
Details	Joints, openings and assembly evidence	Rework at interfaces

Architectural metal wall coverings are the finished metal surfaces of buildings: rainscreen skins, cassette trays, profiled sheets, insulated sandwiches, and interior liners. They are not one product. A wall that works names the metal, the panel format, the joint, the backup, and the drainage path together.

This page is the site map. Name the decision here, then open the cluster that owns the details. The Whole Building Design Guide treats these assemblies as metal panel wall systems. The useful unit is the wall, not a coil or a colour chip.

What this site means by metal wall coverings

Three phrases show up in the same meeting and do not always mean the same thing.

• Metal wall covering is the architectural surface the occupant sees and the weather hits.
• Metal wall panel is the fabricated unit: a sheet, a tray, a composite sandwich, or a factory-insulated module.
• Metal cladding is the system that hangs or fastens that unit to a backup wall, including rails, clips, joints and flashings.

A useful specification writes all three. “Use metal cladding” is not a specification. “0.8 mm PVDF-coated aluminum cassettes on a drained rainscreen, with isolated stainless fixings” is an illustration of specification wording only, not an engineering thickness recommendation or an approved wall design.

This publication stays inside architectural walls. It does not cover metal roofing installation, carports, patio covers, plating shops, or city-by-city contractor pages.

The four questions every project has to answer

Most metal wall arguments reduce to four questions, one for each cluster of this site. The step-by-step order further down puts them in sequence, starting with use. Skipping ahead to a favourite finish is how oil canning, staining, and failed listings get into the building.

1. What material?

Aluminum, steel, stainless steel, corten, zinc and copper are not interchangeable skins with different paint. They differ in density, stiffness, corrosion behaviour, thermal movement, finish range and cost.

Aluminum is the common architectural default because it is light and coating-friendly. Coated steel is usually stiffer and cheaper for profiles and insulated sandwiches. Stainless, zinc and copper are specified when the surface itself is the design, not when a colour card will do. Corten is a patina system with a runoff problem, not a rusted texture overlay.

Open the materials hub when the remaining argument is the metal.

2. What panel system?

The same coil becomes very different walls. Single-skin sheet is one formed face. Metal Composite Material panels bond two thin skins to a core for flatness. Insulated metal panels put insulation between two faces and become part of the enclosure. Rainscreen cladding hangs an outer metal layer over a drained cavity. Cassettes fold trays with concealed joints. Corrugated, perforated and expanded mesh change stiffness, texture and openness.

A rainscreen and an insulated sandwich can both be “metal panels” and still fail each other’s performance tables. Open the systems hub when the remaining argument is format, joints and drainage.

3. Where is it going?

Exterior walls take weather, movement and code listings that interior accent walls do not. Commercial facades add height, public impact and shop-drawing load. Residential cladding often has less access budget and more mixed-material junctions.

Copying an interior lobby spec onto a weather wall, or a house accent spec onto a civic elevation, is a common failure. Open the applications hub when the remaining argument is exposure and building type.

4. How will it be specified?

Cost is an installed-system number. Installation is sequencing, substrate and flashings. Finishes are coating classes and living patinas. Corrosion is couples, salt and cut edges. Oil canning is a visual risk on flat glossy fields. Fire performance is an assembly claim.

Open the design and specification hub when the remaining argument is a number, a listing or a detail that can fail the wall.

How the material and the system interact

Teams often pick a metal first and inherit a system by habit. That is backwards for several common pairs.

Aluminum is the usual face for Metal Composite Material panels because the skins are thin and the core supplies flatness. Coated steel is the usual face for insulated metal panels because the faces work as structure as well as finish. Zinc and copper want ventilation and compatible flashings more than they want a particular tray module. Perforated and expanded metal are screens unless a second weather plane exists behind them.

If the project needs a drained architectural facade, start with rainscreen logic, then choose the tray or composite format, then choose the metal. If the project needs a factory-insulated enclosure, start with insulated metal panels, then accept that the face metal is usually steel. If the project needs a lightweight stone-look interior, metal may not be the right family at all; that fork lives on the comparisons hub.

Interior walls are not small exteriors

Interior metal is specified for impact, hygiene, acoustics, lighting and the quality of the visible joint. It does not need a drained cavity unless the room is wet. It does need a finish that can be cleaned and an attachment that does not oil-can under grazing light.

Exterior metal is specified for water, wind, movement, UV and the listed wall assembly. A PVDF system that is correct on a facade can be the wrong interior cost. An uncoated stainless liner that is correct in a kitchen is the wrong coastal cassette if the alloy and finish were chosen for shine rather than for chlorides.

Write two specifications when the same building has both conditions.

Performance claims that belong in writing

A page that only praises durability is not usable. The claims that matter have a scope.

Weight includes the panel, the rails, and the backup. Renovation projects fail when the sample is light and the subframe is left out of the count.

Corrosion is alloy, coating, cut-edge treatment, fastener metal, and whether dissimilar metals meet in a wet joint. It is not a slogan attached to the metal name. See metal cladding corrosion.

Fire is never “the metal is safe.” Solid sheet, composite cores, foam insulation, and cavities are different layers. This site does not write that metal panels are fireproof. See metal wall panel fire performance.

Flatness is oil canning, stiffening, and gloss. Large, dark, specular fields show waviness that a corrugated profile hides. See oil canning.

Cost moves with gauge, finish, custom corners, access equipment, and labour more than with the published coil price. See metal cladding cost.

How to choose metal wall panels, step by step

Work in this order: use, system, metal, finish, details. Each step narrows the next, and each should leave you with a decision you can write down.

1. Use. Name interior or exterior, the building type, the height and the exposure. Exterior walls carry weather, movement and code listings; interior and decorative metal wall panels carry impact, cleaning and appearance under room light. You leave with an application, from the applications hub.
2. System. Name the weather and drainage job: drained rainscreen skin, insulated sandwich, profiled single skin, or screen. You leave with a panel format and attachment method, from the systems hub.
3. Metal. Name the metal that can do that job in that climate and budget, with its thickness. You leave with a material, from the materials hub.
4. Finish. Name the coating or surface class for the exposure and the warranty terms you need. You leave with a finish line on metal panel finishes.
5. Details. Name movement, corrosion isolation, flashings and the fire listing for the assembly. You leave with specification lines from installation, corrosion and fire performance.

If two families remain after step 3, open the matching comparison. Do not start with a comparison and work backwards into a climate.

When the remaining fork is aluminum versus coated steel, use aluminum vs steel wall panels. When the other finish is stone-look or cement board, use those comparison pages as decision tools, not as a shop directory. When someone writes only “MCM,” open what MCM means in cladding before the specification is typed. In architectural metal walls, MCM means Metal Composite Material, as defined by the Metal Construction Association.

How long do metal wall panels last, and what decides it?

There is no single service-life number for metal wall panels, and this site does not publish one. Service life belongs to the system in its exposure. Six factors decide it:

• The metal and its thickness. The Metal Construction Association’s steel cladding bulletin tells buyers to compare metal thickness, yield strength, metallic coatings and finish systems against the building’s location and end use.
• The metallic coating, where the metal has one. Coated steel depends on its zinc or zinc-alloy layer. The American Galvanizers Association’s atmospheric service-life data describes industrial atmospheres as generally the most aggressive for zinc coatings, with tropical marine air almost as corrosive.
• The finish system — paint chemistry, anodizing or a living patina — and the warranty written for it.
• The site’s exposure: coastal salt, industrial pollution, de-icing spray, sheltered zones that are never rain-washed.
• The detailing: cut edges, fastener metals, dissimilar metals in wet joints, and whether the cavity drains. See metal cladding corrosion.
• Maintenance: whether anyone inspects, cleans and repairs the wall.

Ask the manufacturer for the coating and finish warranties for your exact system and exposure, and read their exclusions. That document is the nearest thing to a life figure that applies to your wall.

Who decides what: designer, manufacturer, building official

Metal wall decisions are split between parties, and gaps between them cause most disputes.

• The design team sets the use, the performance required — wind, movement, water, fire, energy — the system type, and the interfaces with windows, roof and barrier.
• The manufacturer or fabricator supplies tested assemblies, the installation manual and standard details. On commercial work it often also provides engineered panels and subframe under delegated design, as described on commercial metal facades.
• The installer builds to the manual and the approved shop drawings.
• The building official (the authority having jurisdiction) reviews the wall against the adopted codes, including the tested fire assembly where one is required.

A specification that names who owns each item prevents the most common failure: everyone assuming someone else engineered the subframe or detailed the window head.

What to ask a supplier for

This site does not list suppliers, local stockists or prices. Use the existing panel specification checklist to record dimensions and thickness. When you contact a manufacturer or distributor, ask for documents that let you compare quotes on the same basis:

• A datasheet naming the metal, uncoated base thickness, and the metallic coating designation where there is one.
• The finish system and its warranty terms, split by film integrity, color change and, for steel, the metallic coating.
• Test reports or listings for the assembly you will build: fire, wind and water, in the configuration tested.
• The installation manual for the exact system, with its substrate tolerance.
• Standard details for base, openings, corners and parapet.
• A quote itemized on the lines in metal cladding cost: panels, subframe, flashings, access.
• Sample or mockup arrangements, and how replacement panels are matched to the original batch.

What this guide will not do

It does not price a facade from a city name, issue a quote, or rank manufacturers. It does not treat a living patina as a paint colour, and it does not transfer an insulated-panel fire listing onto a single-skin rainscreen. Once a knowledge hub starts selling or localizing, the technical pages stop being usable.

Where to go next

• Choose a metal on the materials hub.
• Choose a format on the systems hub.
• Place the wall on the applications hub.
• Write the limits on the design and specification hub.
• Resolve a fork on the comparisons hub.

If you only open one child page after this one, open the cluster that matches the question you cannot yet answer in a drawing note.