Exposed fastener, wide rib
- How it attaches
- Screwed through the panel face into framing
- Typical placement
- Roofs and walls on most pre-engineered buildings
- Names you may see
- R, PBR and similar manufacturer-specific codes
Reference guide
Panel Profiles Explained
A quote will name a panel by a short code — R, PBR, AG, corrugated, standing seam — and then price it as if you know what that means. This page explains what those names describe, why they are not standardised between manufacturers, and how to compare two proposals that use different ones.
A panel profile is the shape a flat coil of steel is rolled into. That shape decides how the panel stiffens itself, how it laps onto the next sheet, whether the fasteners show, and whether it belongs on a roof, a wall or an interior liner.
The complication for buyers is naming. Profile names are manufacturer trade descriptions, not an industry standard, and two suppliers can use the same letter for panels that are not identical. This page gives you the vocabulary to ask the right question rather than a table of numbers that would only be true for one company's product.
Written by Gary Thompson · Steel Building Research EditorSteel Building Research EditorReviewed by Find Steel Buildings Editorial Team
Why there are no numbers on this page
Coverage widths, rib heights, gauges, panel spans and load tables belong to the specific panel being quoted, and they differ between manufacturers using the same profile name. Ask for the panel's own data sheet by name and gauge rather than relying on any general figure — including one from us.
Rib families in cross-section
- 01Wide rib, exposed fastener — screwed through the flat of the panel, screw heads visible
- 02Corrugated, exposed fastener — continuous wave form, screwed through the panel face
- 03Standing seam, concealed — fixed at or under the raised seam, no field penetration
What a profile actually describes
Sheet steel on its own is floppy. Rolling ribs into it makes it stiff in one direction, and the depth, spacing and shape of those ribs are what a profile name is shorthand for. Everything else about the panel — the steel, the coating, the colour, the length — is specified separately.
So when a proposal says the roof is one profile and the walls are another, that is not marketing. It is a statement about rib geometry, and it has consequences for how the sheets lap, what trim fits, how the panel is fixed down and how it will look.
- Rib depth and spacing
- How tall the ribs are and how far apart they sit. This is the main structural difference between profiles.
- Lap detail
- How one sheet joins the next — a simple overlap, a purpose-made side lap, or a mechanically joined seam.
- Fastener visibility
- Whether screws pass through the face of the panel or are hidden under the seam.
- Face appearance
- The flat width between ribs, which is what you actually see from the ground.
The three families you will be quoted
Almost every panel a steel building buyer sees falls into one of three families. Knowing which family a name belongs to is more useful than memorising the name itself.
Exposed-fastener panels are the default on most pre-engineered buildings: the sheet is screwed through its face into the framing, and the screw heads are visible. Concealed-fastener and standing-seam panels attach at or under the seam, so no fastener penetrates the weather surface in the field of the roof. Liner and interior panels are lighter sheets used on the inside face of a wall or ceiling, for appearance, protection or to hold insulation in place.
- Exposed fastener
- Screwed through the panel face. R, PBR, AG and corrugated profiles are usually in this family.
- Concealed fastener / standing seam
- Attached at the seam with clips or concealed fixings; the roof surface has no field penetrations.
- Liner and interior
- Lighter profiles installed on the inside face. Not a weather barrier and not interchangeable with exterior panels.
Profile families at a glance
Names vary between manufacturers; families do not. Identify the family first, then ask for the specific data sheet.
Exposed fastener, corrugated
- How it attaches
- Screwed through the panel face
- Typical placement
- Walls, agricultural buildings, accent and wainscot areas
- Names you may see
- Corrugated, AG, wave profiles
Concealed fastener / standing seam
- How it attaches
- Clips or fixings under a raised or mechanically joined seam
- Typical placement
- Roofs where a fastener-free weather surface is wanted
- Names you may see
- Standing seam, snap-lock, mechanically seamed
Liner and interior
- How it attaches
- Fixed to the inside face of framing
- Typical placement
- Interior walls and ceilings, insulation retention
- Names you may see
- Liner panel, interior panel
Family placement is a general description of common practice, not a specification. The panel used on your building is whatever the engineered system and the manufacturer's documentation say it is.
The fields that make two panel quotes comparable
Manufacturer and exact profile name
- Why it matters
- Profile names are trade names. Without the manufacturer, the name identifies nothing.
Steel thickness (gauge)
- Why it matters
- The single most common quiet difference between a cheaper and a dearer panel line.
Coating and paint system
- Why it matters
- Determines corrosion and colour performance, and is where warranty terms actually live.
Finish warranty document
- Why it matters
- Panel warranties are issued by the coating or panel manufacturer, not by the building seller.
Roof, wall and liner panels listed separately
- Why it matters
- One building commonly uses several profiles; a single line item can hide a substitution.
Reading profile names without assuming they match
Manufacturers publish their profiles by name — MBCI, for example, lists panel profiles including PBR, R and AG among its product families, and McElroy Metal publishes its own separately named profile range. Both are real products with real data sheets; neither name is an industry standard that binds anyone else.
The practical consequence is simple. If two quotes both say "R panel", you have not yet learned that they are the same panel. If one says PBR and one says R, you have not necessarily learned that they are different in a way that matters to you. The only way to know is to get the manufacturer and the profile name together, and then read that manufacturer's sheet.
This is also the honest reason we do not publish a universal profile table. Any table that claimed to give one rib height for "R panel" across the industry would be wrong for somebody's building.
Where each family normally ends up
Profile choice usually follows the job rather than preference. Exposed-fastener profiles dominate roofs and walls on utility, agricultural and workshop buildings because they are quick to install and simple to repair. Standing seam appears where the roof is expected to move thermally, where a longer service expectation is being bought, or where the appearance of a fastener-free roof matters.
Wall panels are a separate decision from roof panels even when the profile name is the same, because a wall is not walked on, sheds water differently and is seen from close range. It is completely normal for one building to use three profiles: one on the roof, one on the exterior walls and one as a liner inside.
What actually moves the price between two panel quotes
Profile is only one of the variables. The steel thickness, the coating system, the finish, the panel length and whether the sheets are factory cut to length all sit behind the same line on a proposal. A cheaper panel line can mean a different profile, or the same profile in a lighter gauge, or a different paint system with a different warranty.
Because component pricing is not what this section of the site covers, treat the profile conversation as a specification exercise: get the four or five fields below stated identically on every quote, and let the price difference then mean something.
Terms used on this page
- Profile
- The rolled shape of the panel — the rib pattern, not the material.
- Rib
- The raised fold that stiffens the sheet and forms the side lap.
- Side lap
- The joint where one sheet overlaps or engages the next.
- Exposed fastener
- A screw driven through the face of the panel, visible from outside.
- Concealed fastener
- A fixing hidden beneath the seam, leaving no field penetration in the weather surface.
- Liner panel
- An interior sheet on the inside face of the framing; not a weather barrier.
What to confirm before you compare quotes
Manufacturer plus profile
Both together, on every quote. A profile name on its own does not identify a panel.
Gauge
Stated for roof, wall and liner panels separately.
Coating system
Named, with the document that states its warranty terms.
Panel schedule
Which profile goes where — roof, walls, wainscot, liner.
Trim compatibility
That the trim package quoted is made for the profiles quoted.
Frequently asked questions
Not necessarily, and not automatically between manufacturers. Both names appear in manufacturer profile ranges — MBCI, for instance, publishes PBR, R and AG among its profiles — but the names are trade descriptions rather than an industry standard. Ask for the manufacturer and the profile name together and read that company's data sheet for the panel actually being supplied.
There is no single best profile, and any page that names one is guessing about your building. The realistic choice is between an exposed-fastener panel and a concealed-fastener or standing-seam system, and that turns on how the building is used, how long you expect the roof to last untouched, and what the engineered system supports. Our roof panel guide sets out that comparison.
Mixing is normal rather than unusual: one profile on the roof, another on the walls, a corrugated profile as wainscot and a lighter liner panel inside is a common combination. What matters is that the trim, closures and fasteners quoted are made for the profiles quoted, and that the panel schedule states which goes where.
Because it is a property of one manufacturer's product, not of the name. Two companies can sell panels under similar names with different rib geometry, coverage and gauge options. The number you want exists — it is on the data sheet for the exact panel in your quote — and asking for that sheet is a reasonable request that any supplier can meet.
It can affect how the assembly goes together, because insulation systems are installed against framing and beneath or within the panel, and liner panels are sometimes what holds a system in place. Treat panel and insulation as one conversation with the supplier rather than two separate purchases.
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.
Manufacturer profile ranges exist by name · Tier 2
MBCI publishes named metal panel profiles, including PBR, R and AG profiles, in its own product literature.
Establishes that these names are manufacturer product names. No dimension, gauge or performance figure is taken from the source.
MBCI — metal panel productsProfile naming is not standardised · Tier 2
Different manufacturers publish their own separately named panel profile ranges rather than a shared industry catalogue.
Supports the naming observation only. It does not authorise any equivalence or difference claim between two named profiles.
McElroy Metal — panel product rangeMetal building systems context · Tier 1
Metal building systems, including roof and wall panel assemblies, are covered by technical material published by the Metal Building Manufacturers Association.
Points to the industry body. No provision of any manual is quoted or applied.
Metal Building Manufacturers AssociationNot verified · Tier 4
No rib height, coverage width, gauge, panel span or load value is published on this page, and none was verified for any building.
Records a deliberate absence. These values belong to the data sheet for the specific panel being quoted.
Find Steel Buildings editorial policyWhere to go next
Next step
Roof panel systems compared
Profile is the vocabulary; the roof system decision is the next real choice.
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Panel names only become comparable once every proposal states the manufacturer, profile and gauge. Fix the specification first, then compare.
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.