Profile
- Options
- Wide rib, corrugated, concealed fastener
- What it mainly affects
- Appearance, fastener visibility, trim compatibility
Selection guide
Wall Panels
Walls are seen from three feet away, get knocked into, and are what the building looks like from the road. This guide covers the exterior panel decision on its own terms rather than treating walls as leftover roof.
It is easy to assume the walls of a steel building are whatever the roof is. Often they are the same profile family, but the decision is genuinely different: a wall is not walked on, sheds water down its own face, meets the ground, carries every opening, and is the surface people actually look at and touch.
This page covers what changes when you specify walls deliberately — orientation, profile choice, wainscot, and whether you need a liner on the inside.
Written by Gary Thompson · Steel Building Research EditorSteel Building Research EditorReviewed by Find Steel Buildings Editorial Team
Why walls are a separate decision
A roof panel is chosen mostly for water and longevity. A wall panel is chosen for those too, but appearance, impact resistance at low level and the interface with openings carry far more weight. That is why buildings that use a plain wide-rib panel on the roof often use something else — or the same profile in a different orientation and colour — on the walls.
Walls also fix to girts rather than purlins, and they are interrupted by every door, window and louver. The trim burden per square foot is much higher on a wall than on a roof.
What a wall is made of
- 01Column — primary frame member
- 02Girt — horizontal secondary framing the panels fix to
- 03Exterior wall panel
- 04Wainscot transition — where a lower band of different panel or colour meets the upper wall
- 05Liner panel — optional interior sheet; not a weather barrier
- 06Base trim at the slab
Vertical or horizontal panels
Most steel building walls run vertically: panels stand from base to eave, water runs straight down the ribs, and the base detail is a single continuous line. Horizontal panels run along the wall and are chosen for appearance, for a particular architectural language, or where a design wants uninterrupted horizontal bands.
The decision is not purely aesthetic. Orientation changes how many horizontal joints exist for water to test, how the panels lap, how the base detail works, and how the framing behind them has to be arranged — which is why it has to be settled with the supplier before engineering rather than at colour-selection stage.
- Vertical
- The common default. Continuous drainage path, simple base line, straightforward at openings.
- Horizontal
- Chosen for appearance. Introduces horizontal joints and a different framing arrangement.
Wainscot: the two-tone lower band
A wainscot is a band of different panel or colour running along the bottom of the wall. It exists for two reasons: it changes the look of a large plain elevation, and it puts a defined line where the wall takes the most abuse — vehicle doors, machinery, splash-back, mowers.
Where a wainscot is used, there is a transition line to detail. That transition needs its own trim and closure, and it is a common place for a quote to be quietly incomplete.
The four wall decisions
Orientation
- Options
- Vertical or horizontal
- What it mainly affects
- Drainage path, joint count, framing arrangement, look
Wainscot
- Options
- None, contrast colour, different profile
- What it mainly affects
- Appearance and low-level durability; adds a transition detail
Liner
- Options
- None, partial, full height
- What it mainly affects
- Interior finish, insulation protection, cleanability, cost
Availability of each option depends on the manufacturer and on the engineered building system.
Fields to extract from each wall quote
Wall profile and gauge, stated separately from roof
- Why
- Roof and wall are commonly different and commonly merged into one line.
Coating system and colour
- Why
- Determines finish warranty and how the building ages.
Wainscot: included or excluded
- Why
- Includes the transition trim, not just the panel.
Liner: extent and profile
- Why
- Full height, partial or none is a large scope difference.
Opening trim
- Why
- Wall trim burden is concentrated around doors and windows.
Liner panels and what they are for
A liner panel is a lighter sheet fixed to the inside face of the wall framing. It is not a weather barrier. It exists to give a cleanable, hard-wearing interior surface, to protect insulation from damage and daylight, and to make the inside of the building look finished.
Liner is a genuine cost decision rather than a default. It is common in workshops, food-related and customer-facing spaces, and often skipped in pure storage. Where insulation is installed, the liner also affects how that system is held and how it is inspected later, so decide the two together.
Making two wall quotes comparable
Wall panels are quoted at a per-building level, so a difference in gauge, coating or liner scope disappears into a single number. The fields in the table below are the ones worth extracting from each proposal.
What the engineered system decides
Girt arrangement, panel spans, fastener patterns and the loads the wall must resist are part of your building's engineered design. Final spacing and sizing are determined by the engineered building system.
Settle these before the building is engineered
- 01Wall panels listed separately. Profile, gauge and coating stated apart from the roof.
- 02Orientation confirmed. Before engineering, not at colour selection.
- 03Wainscot scope. Panel and transition trim both included if a wainscot is shown.
- 04Liner extent. Full, partial or none, with the profile named.
- 05Colour matching. Trim coating matches the wall panel coating system.
Terms used on this page
- Girt
- The horizontal secondary framing member that wall panels fix to.
- Wainscot
- A lower band of contrasting panel or colour along the base of a wall.
- Liner panel
- A lighter interior sheet on the inside face of the wall framing.
- Orientation
- Whether panels run vertically from base to eave or horizontally along the wall.
Frequently asked questions
Yes, and on many buildings they are. Roof and wall face different demands — a wall is seen close up, takes impact at low level and is interrupted by every opening — so a different profile, colour or orientation on the walls is completely normal. What matters is that trim and closures are supplied for the profiles actually used on each plane.
Vertical is the common default because water runs straight down the ribs and the base detail is one continuous line. Horizontal is an appearance choice that introduces more horizontal joints and a different framing arrangement behind the panel. Either can be right; the decision needs to be made before the building is engineered rather than afterwards.
It is a band of different panel or contrasting colour along the bottom of the wall. It breaks up a large plain elevation and puts a deliberate line where the wall takes most of its knocks. Remember that a wainscot creates a transition joint that needs its own trim and closure, and confirm those are in the quote.
Not always. Liner gives a cleanable, hard-wearing interior surface and protects insulation from damage, which matters in workshops and customer-facing spaces and matters much less in cold storage. It is a real cost line, so decide it deliberately alongside the insulation decision rather than letting it default either way.
That is set by your building's engineered design, not by the panel choice, and it varies with the building's geometry and the conditions at your site. Final spacing and sizing are determined by the engineered building system. If a supplier states a spacing before the building is engineered, treat it as an assumption to confirm.
Verification and sources
Every material statement on this page maps to a published source, and each record states what that source does not cover. Where something was not verified it is recorded as not verified rather than estimated.
Wall panels attach to secondary framing · Tier 2
In metal building systems, wall panels are supported by girts, the horizontal secondary framing members spanning between primary frames.
Supports the structural relationship only. No spacing, span or member size is taken from the source.
Butler MFG Parts — purlins and girtsWall panel product families · Tier 2
Panel manufacturers publish distinct wall panel and liner panel product families alongside roof panels.
Establishes that wall and liner panels are distinct products. No dimension or performance figure is used.
MBCI — wall and liner panelsMetal building systems scope · Tier 1
Wall systems are treated as an engineered part of the metal building system by the industry's manufacturers association.
Establishes the engineering boundary. No manual provision is quoted or applied.
Metal Building Manufacturers AssociationNot verified · Tier 4
No girt spacing, panel span, gauge or fastener pattern is published on this page.
Records a deliberate absence. These are properties of the engineered building.
Find Steel Buildings editorial policyWhere to go next
Next step
Panel profiles explained
Profile vocabulary is the prerequisite for a real wall specification.
Also useful
Compare building quotes
Wall scope differences only surface while quotes are open.
Planning a building?
Compare steel building quotes
Walls are where quote differences hide, because one line covers profile, gauge, coating, wainscot and liner. Ask for them separately.
Requests go to Find Steel Buildings so we can compare whole-building options. Find Steel Buildings does not sell individual components, no component manufacturer or named company receives your request, and we are not affiliated with the companies referenced on this page.