R-Panel is a trapezoidal, exposed-fastener metal roofing and siding panel with 36 inches of net coverage and 1.25-inch ribs spaced on 12-inch centers. It is the most widely stocked metal panel profile in the United States, sold under the generic name R-Panel and the original trade name Regent Rib. Manufacturers including McElroy Metal, Metal Sales, and Western States Metal Roofing all roll a version of it. This guide covers the exact dimensions, the gauge choices, real 2026 pricing including installed cost, and the one detail that decides whether R-Panel belongs on your roof or only on your walls.
What is R-Panel roofing?
R-Panel roofing is a through-fastened steel panel with wide, flat pans separated by tall trapezoidal ribs, screwed directly through the face of the metal into the roof deck or purlins. Each panel covers 36 inches, so three ribs land across every panel on 12-inch centers. It is the workhorse profile for agricultural buildings, pole barns, workshops, warehouses, and budget-conscious homes, and it installs faster and cheaper than a concealed-fastener system.
The name goes back to the Regent Rib profile, which the industry shortened to R-Panel. Because the geometry is not patented, dozens of mills roll a nearly identical panel, which is why pricing is competitive and material is easy to source regionally. R-Panel sits in the same family as corrugated roof panels and U-Panel, all of which are exposed-fastener profiles that lap rib over rib.
R-Panel dimensions and profile specs
R-Panel runs 36 inches of net coverage with a 1.25-inch rib height, formed from a coil width of roughly 40 to 48 inches before rollforming. Panels are cut to length on demand, commonly from 3 feet up to 40 feet or more, which lets a single panel run eave to ridge on most roofs. The typical minimum recommended slope is 3:12, though some manufacturers permit lower pitches when butyl tape seals the sidelaps.
| Spec | R-Panel figure |
|---|---|
| Net coverage width | 36 in |
| Rib height | 1.25 in |
| Rib spacing | 12 in on center (3 ribs per panel) |
| Coil width (pre-form) | 40 to 48 in |
| Panel length | Custom, about 3 ft to 40+ ft |
| Minimum roof slope | 3:12 typical (lower with sealant tape on some systems) |
| Fastener type | Exposed, gasketed screws through the flat |
Coverage width matters for ordering. To sheet a roof, divide the total roof width by 3 feet to get the panel count, then add panels for overlaps and waste. The Roofing Brief metal roofing calculator handles the coverage math and the trim list so you order the right quantity the first time.
What gauge is R-Panel?
R-Panel is stocked in 29, 26, 24, and 22 gauge, and lower gauge numbers mean thicker steel. 26 gauge is the most common choice for roofing because it balances stiffness and cost, while 29 gauge is a light-duty option for sheds and short spans and 22 gauge is reserved for heavy structural runs. Gauge choice depends on span between supports, snow and wind load, and budget.
| Gauge | Relative thickness | Typical use |
|---|---|---|
| 29 ga | Thinnest | Sheds, carports, short-span outbuildings |
| 26 ga | Standard | Most residential and light commercial roofs |
| 24 ga | Heavy | Wider spans, higher wind and snow zones |
| 22 ga | Thickest | Structural and demanding industrial runs |
Thicker steel resists oil-canning and foot traffic denting but costs more per square. For a fuller breakdown of how gauge and coating drive per-sheet pricing across profiles, see the guide to roofing sheet metal gauge and price.
R-Panel vs PBR panel: the purlin bearing leg
The single detail that separates R-Panel from PBR panel is a small extended lip called the purlin bearing rib, or purlin bearing leg. PBR panel adds this leg under the major rib so the panel laps under the next panel and rests flat on the purlin, closing the void at the sidelap. Standard R-Panel laps major rib directly over major rib with no bearing leg, which leaves a small gap that can wick water on a low-slope roof. Both panels share the same 36-inch coverage and 1.25-inch rib, and they usually cost within 2 to 3 percent of each other.
That gap is why many suppliers spec PBR for roofing and reserve plain R-Panel for walls. On a wall, water sheds off and the open sidelap never matters. On a roof, an ungasketed rib-over-rib overlap is a candidate leak point over time, especially below 3:12. If a supplier quotes “R-Panel” for a roof, confirm whether they are actually rolling the PBR version, because the two names are used loosely in the field.
| Feature | R-Panel | PBR panel |
|---|---|---|
| Coverage width | 36 in | 36 in |
| Rib height | 1.25 in | 1.25 in |
| Purlin bearing leg | No | Yes |
| Sidelap | Rib over rib, small void | Nested, closed lap |
| Best use | Walls and siding | Roofing and siding |
| Price difference | Baseline | About 2 to 3% more |
R-Panel vs corrugated and U-Panel
R-Panel, corrugated, and U-Panel are all exposed-fastener profiles, but their rib shapes change stiffness and price. Corrugated uses a rounded 7/8-inch wave, U-Panel uses a squared 3/4-inch rib, and R-Panel uses a taller 1.25-inch trapezoidal rib that adds strength per gauge. R-Panel typically runs 15 to 20 percent more than corrugated and roughly 50 percent less than standing seam.
| Profile | Rib | Coverage | Relative cost |
|---|---|---|---|
| Corrugated | 7/8 in rounded | ~24 to 26 in | Lowest |
| U-Panel | 3/4 in squared | 36 in | Low |
| R-Panel / PBR | 1.25 in trapezoidal | 36 in | Low to mid |
| Standing seam | 1.5 to 2 in concealed | 12 to 18 in | Highest |
If you want the concealed-fastener look and the lowest long-term maintenance, R-Panel is not the profile to chase. For a screw-down system on a budget, it wins. See how the exposed-fastener family compares to concealed systems in the guide to screw-down metal roofing versus standing seam.
How much does R-Panel cost in 2026?
R-Panel material runs about $2.00 to $5.00 per square foot in 2026, driven by gauge and paint system. Silicone-modified polyester (SMP) paint sits at the low end, while premium PVDF (Kynar) finishes cost more and hold color longer. Installed with labor, fasteners, closures, and trim, expect roughly $4.00 to $7.00 per square foot in most markets, though pricing varies by region, roof complexity, and crew.
| Panel spec | Material per sq ft |
|---|---|
| 26 ga, SMP paint | $2.00 to $2.50 |
| 24 ga, SMP paint | $2.50 to $3.00 |
| 24 ga, PVDF paint | $2.50 to $3.50 |
| 22 ga, PVDF paint | $3.50 to $5.00 |
The material sticker is only part of an installed number. A realistic per-square (100 square feet) buildup adds gasketed screws, ridge and eave trim, closure strips, underlayment, and labor. Fasteners alone typically add $0.10 to $0.20 per square foot, and trim on a cut-up roof can add more than the panels on a simple gable. Get every line item itemized before comparing bids.
Exposed fasteners: screw count, gaskets, and lifespan
R-Panel is screwed through the face of the metal with gasketed screws, and a common planning figure is roughly 80 screws per square (100 square feet) for a through-fastened panel, placed in the flat next to the ribs and along each purlin or the deck. Every one of those screws carries a rubber EPDM washer that seals the hole, and every washer is a wear part exposed to sun and heat.
The maintenance reality that most spec sheets skip: EPDM washers commonly degrade under UV in about 15 to 20 years, well before the steel or the paint fails. When washers crack or the screws back out from thermal cycling, the panel starts to leak at the fastener, and the fix is a full re-screw with oversized gasketed fasteners. Budget for that mid-life service when you compare R-Panel against a concealed-fastener system that has no exposed penetrations.
- Plan about 80 gasketed screws per square, set in the flat pan, not on the rib.
- Drive each screw until the washer compresses flush, not crushed and not proud.
- Inspect washers every few years, especially on south and west exposures.
- Re-screw with larger-diameter gasketed fasteners once washers begin to crack.
When R-Panel is the right choice
R-Panel is the right pick when you want durable metal on a 3:12 or steeper roof at the lowest material cost and can accept exposed fasteners and periodic screw maintenance. It fits agricultural buildings, pole barns, workshops, garages, warehouses, and budget residential roofs. It is the wrong pick when you want a concealed-fastener look, a very low slope, or a roof you never want to service.
- Choose PBR over plain R-Panel for any roof so the purlin bearing leg closes the sidelap.
- Choose R-Panel for walls and siding where the open sidelap does not matter.
- Choose standing seam instead if you want concealed fasteners and minimal long-term maintenance.
- Step up to 24 gauge in high wind or heavy snow zones or on wider purlin spacing.
R-Panel and PBR are only two entries in a wider field. Compare them against the full range in the guide to metal roofing panel types and profiles, and see how the profile fits larger buildings in the overview of commercial metal roofing systems.
Frequently asked questions
What is R-Panel roofing?
R-Panel roofing is a trapezoidal, exposed-fastener steel panel with 36 inches of net coverage and 1.25-inch ribs on 12-inch centers, screwed through the face into the deck or purlins. It is the most common metal profile in the United States, used on barns, workshops, warehouses, and budget homes. It installs faster and costs less than a concealed-fastener standing seam system.
What is the difference between R-Panel and PBR panel?
PBR panel adds a purlin bearing leg under the major rib that nests under the next panel and closes the sidelap, while plain R-Panel laps rib over rib and leaves a small void. Both share 36-inch coverage and a 1.25-inch rib and cost within 2 to 3 percent of each other. PBR is specified for roofing, and R-Panel is often reserved for walls.
How much does R-Panel cost?
R-Panel material runs about $2.00 to $5.00 per square foot in 2026 depending on gauge and paint, with 26-gauge SMP at the low end and 22-gauge PVDF at the top. Installed with labor, fasteners, and trim, most roofs land near $4.00 to $7.00 per square foot. Actual pricing varies by region, roof complexity, and crew.
What gauge is R-Panel?
R-Panel is stocked in 29, 26, 24, and 22 gauge, where lower numbers mean thicker steel. 26 gauge is the standard for most roofs, 29 gauge suits sheds and short spans, and 24 or 22 gauge handles wider spans and higher wind or snow loads. Thicker gauge resists denting and oil-canning but adds cost per square.
What is the minimum roof pitch for R-Panel?
The typical minimum recommended slope for R-Panel is 3:12, though some manufacturers permit lower pitches when butyl sealant tape closes the sidelaps and endlaps. Below the recommended slope, water drains slowly and the exposed rib-over-rib overlap on plain R-Panel becomes a leak risk. PBR panel and taped seams extend the usable low-slope range.
Can R-Panel be used for roofing?
R-Panel can be used for roofing, but the PBR version with the purlin bearing leg is the better roof choice because it closes the sidelap void that plain R-Panel leaves. Many suppliers roll only the PBR profile for roofs and hold plain R-Panel for walls. On any roof, confirm the panel has the bearing leg before you buy.
How long do R-Panel roofs last?
An R-Panel roof can last 30 to 45 years on the steel and paint, but the exposed gasketed fasteners are the limiting part. EPDM washers commonly degrade under UV in about 15 to 20 years, so plan for a mid-life re-screw with larger gasketed fasteners. A concealed-fastener system avoids that service but costs more upfront.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.