A PBR panel is an exposed-fastener metal roofing and siding panel with 36 inches of net coverage, a 1.25-inch rib height, and major ribs spaced 12 inches on center. The letters stand for Purlin Bearing Rib, the small return leg on the panel edge that makes it strong enough for roofing, not just walls. It is the default panel on most metal buildings, pole barns, and light-commercial roofs in the United States, and it is often sold under the names R-panel, PBR-panel, or R-PBR.
This page puts the numbers a buyer actually needs in one place: the exact dimensions, how a PBR panel differs from a plain R-panel, gauge and finish options, minimum roof slope, fastening, and 2026 pricing.
What does PBR stand for in metal roofing?
PBR stands for Purlin Bearing Rib. It describes a short leg formed into the underlapping edge of the panel that rests on the purlin or the panel beneath it. That leg carries the sidelap load metal-to-metal instead of pinching the two sheets together at a screw, which is the single feature that separates a roofing-grade panel from a wall-only one.
The profile itself is often called an R-panel, a generic industry name popularized by manufacturers including MBCI, Ceco, and Union Corrugating. When you see PBR, R-PBR, or “R-panel with purlin bearing leg,” they refer to the same rib pattern with the added bearing rib. A panel labeled only R-panel usually lacks that leg.
PBR panel dimensions
A standard PBR panel covers 36 inches wide, stands 1.25 inches tall at the major ribs, and repeats those ribs every 12 inches. Panels are roll-formed and cut to length on order, commonly up to 40 feet or more, so a run often installs as a single sheet from eave to ridge. These metal panel dimensions are consistent across most North American manufacturers, which is why parts and trim interchange between brands.
| Spec | Standard PBR panel |
|---|---|
| Net coverage width | 36 in |
| Overall (pre-lap) width | about 38 to 39 in |
| Major rib height | 1.25 in (1-1/4 in) |
| Major rib spacing | 12 in on center |
| Minor (stiffening) ribs | 2 per pan, between majors |
| Common gauges | 29, 26, 24, 22 |
| Typical length | cut to order, up to 40+ ft |
| Fastener type | exposed self-drilling screw with EPDM washer |
PBR panel vs R-panel: the difference is the leg
PBR and R-panel share the exact same 36-inch, 1.25-inch, 12-inch profile. The only structural difference is the purlin bearing leg on the PBR. That leg gives the underlapping panel a bearing surface at the sidelap, so a true PBR panel is rated for roofing while a bare R-panel is generally sold for walls and siding only.
The leg does three concrete jobs. It locks adjacent panels metal-to-metal so the seam does not crush when the screw is driven, it blocks wind-driven rain from tracking up the lap, and it raises uplift resistance under wind load. Skip the leg on a roof and you get a weaker sidelap that is more prone to leaks and fastener fatigue.
| Feature | PBR panel | R-panel (no leg) |
|---|---|---|
| Profile and coverage | 36 in, 1.25 in rib | 36 in, 1.25 in rib |
| Purlin bearing leg | Yes | No |
| Rated for roofing | Yes | Siding and walls only |
| Sidelap strength | Metal-to-metal bearing | Screw-clamped only |
| Typical use | Metal building roofs, barns, walls | Wall cladding, liner |
PBR vs corrugated, U-panel, and 7.2 panel
PBR is the workhorse exposed-fastener profile, but it is not the only one. Corrugated has a rounded wave and a low profile, U-panel runs a shorter rib for a cleaner residential look, and 7.2 panel uses a deep, widely spaced rib for structural spans. Choosing among them comes down to rib height, span capacity, and appearance rather than base material.
| Profile | Rib height | Coverage | Best fit |
|---|---|---|---|
| PBR / R-panel | 1.25 in | 36 in | Metal buildings, barns, light commercial |
| Corrugated (7/8 in) | 0.875 in | varies (24 to 36 in) | Agricultural, rustic, accent walls |
| U-panel | 0.75 in | 36 in | Budget residential and shed roofs |
| 7.2 panel | 1.5 in | 36 in | Long spans, structural roof and wall |
For a wider walk through every rib pattern and metal type, see our guide to metal roofing profiles, and compare the rounded option directly in our corrugated roof panels breakdown.
Gauge and finish options
PBR panels come in 29, 26, 24, and 22 gauge, and the number runs backward: a lower gauge is thicker steel. 26 gauge (about 0.0179 inch) is the standard for most metal building roofs, 29 gauge is the budget option common on sheds and barns, and 24 or 22 gauge suits high-wind, high-snow, or commercial jobs.
- 29 gauge (about 0.0142 in): lightest and cheapest, fine for low-wind sheds and agricultural buildings.
- 26 gauge (about 0.0179 in): the default for residential and light-commercial roofing.
- 24 gauge (about 0.0239 in): stiffer, better dent and oil-canning resistance, common on commercial spec.
- 22 gauge (about 0.0299 in): heaviest, used for the longest spans and severe wind or snow loads.
Finishes fall into three tiers: bare Galvalume (an aluminum-zinc coated steel), painted silicone-modified polyester (SMP) for most colors, and PVDF (often sold as Kynar 500) for premium fade and chalk resistance. If you are weighing steel thickness, our 26 versus 29 gauge comparison covers where the extra thickness pays off.
Can you use a PBR panel for roofing, and at what slope?
Yes. A true PBR panel with its purlin bearing leg is rated for roofing, which is the whole point of the profile. It installs over open framing (purlins) or a solid deck, and the exposed screws pass through the flat pan of the panel with the sidelap fastened through the raised leg. This is a screw-down metal roof, so it moves and seals differently than a concealed-fastener standing seam.
Minimum roof slope typically runs from 1/4:12 to 1:12 depending on the manufacturer and whether lap sealant (butyl tape) is used at the sidelaps. Always confirm the panel maker’s published minimum before you order, because warranty coverage often depends on it. Fastener counts land around 60 to 80 screws per square (100 square feet) once field and lap screws are added.
For the install logic behind screw placement, see how many screws per square a metal roof needs, and read how the screw-down system compares to standing seam on lifespan and movement.
PBR panel cost in 2026
PBR panel material runs roughly $1.30 to $2.75 per square foot in 2026, with bare Galvalume at the low end and painted or PVDF panels at the top. Installed on a metal building roof, expect roughly $4 to $8 per square foot including fasteners, trim, and labor. Prices vary by region, gauge, finish, order size, and steel commodity swings, so treat these as planning ranges, not quotes.
| Item | 2026 range (per sq ft) |
|---|---|
| Bare Galvalume, 29 to 26 ga (panel only) | $1.30 to $2.00 |
| Painted SMP, 26 to 24 ga (panel only) | $1.75 to $2.75 |
| Trim, screws, closures (added) | $0.50 to $1.25 |
| Installed on metal building roof | $4 to $8 |
Who a PBR panel is right for
PBR panel is the best value in metal roofing for anyone putting a durable roof on a simple, rectangular building. It is engineered for metal buildings, barns, garages, shops, and light-commercial structures where a clean modern rib and a low price matter more than the hidden-fastener look of standing seam.
It is a weaker fit where appearance is the priority or the roof is steep and highly visible from the street, because the exposed screws and washers are part of the look and are a maintenance item over 20 to 40 years. On those jobs a concealed-fastener panel is often worth the premium. On a barn, shop, or metal-building roof, PBR is usually the panel to beat.
Frequently asked questions
What does PBR stand for on a metal panel? PBR stands for Purlin Bearing Rib. It refers to a short leg formed into the panel’s underlapping edge that bears on the purlin or the panel below it. That leg carries the sidelap load metal-to-metal, which is what qualifies the panel for roofing rather than walls only. The base profile is the same 36-inch, 1.25-inch R-panel shape.
What is the difference between a PBR panel and an R-panel? They share the identical 36-inch coverage and 1.25-inch rib profile. The difference is the purlin bearing leg: a PBR panel has it, a plain R-panel does not. That leg makes the PBR strong enough and weathertight enough for roofing, while a bare R-panel is generally rated for siding and walls only.
What is the coverage width of a PBR panel? A PBR panel covers 36 inches net, with an overall pre-lap width of about 38 to 39 inches. The major ribs stand 1.25 inches tall and repeat every 12 inches on center, with smaller stiffening ribs in the flat pan between them. Those dimensions are standard across most manufacturers.
What gauge is a PBR panel? PBR panels come in 29, 26, 24, and 22 gauge, where a lower number means thicker steel. 26 gauge is the standard for most roofs, 29 gauge is the budget choice for sheds and barns, and 24 or 22 gauge is used for commercial jobs and high wind or snow loads.
What is the minimum roof slope for a PBR panel? Minimum slope typically ranges from 1/4:12 to 1:12 depending on the manufacturer and whether butyl lap sealant is used at the sidelaps. Confirm the published minimum for your specific panel before ordering, because low-slope installs often require sealant and specific lap details to keep the warranty valid.
How many screws does a PBR roof need per square? A PBR roof usually takes about 60 to 80 exposed fasteners per square (100 square feet) once field screws and sidelap screws are counted. Screws pass through the flat pan of the panel for roofing, with the sidelap fastened through the raised leg. Use screws with EPDM washers and follow the manufacturer’s pattern.
Is a PBR panel good for a house? A PBR panel can roof a house and does so affordably, but it shows exposed fasteners and reads more utilitarian than a standing seam roof. It is an excellent fit for garages, shops, barns, and simple gable homes on a budget. Where curb appeal and a hidden-fastener look drive the decision, a concealed-fastener panel is often the better pick.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.