Max-Rib

Max-Rib is an exposed-fastener metal panel made by McElroy Metal for roofs and walls. It is a low-profile ribbed panel, set apart from standing-seam systems by its exposed fasteners and its shallow ribs. The panel is also used as a liner. Listed uses include residential, agricultural and light commercial roofs and walls, post-frame and utility buildings, retrofit and new construction, and architectural accents and siding.

Within the metal roof panel family, Max-Rib belongs to the exposed-fastener metal roof panels that McElroy Metal sells alongside its Mega-Rib, Modern-Rib, R-Panel, U-Panel, 5V, Mesa, M-Cor, Multi-Cor and Multi-Rib profiles. The panel is roll formed in the factory, and onsite forming is not available.

The panel is listed as a roofing panel, a wall panel and a liner. It also appears in the McElroy range of exposed-fastener wall panels.

• Rib height: 3/4 inch.
• Major rib spacing: 9 inches on center.
• Cover width: 36 inches.
• Factory panel length: up to 50 feet, depending on the manufacturing facility. An earlier edition of the product data gives standard lengths up to 40 feet, with longer lengths by inquiry.

The panel profile drawing shows foam inside and outside closures at the ends of the panel.

• Seam type: exposed-fastened wall and roof
• Onsite forming: not available

The standard material is 29 gauge ASTM A792 steel, an 80 ksi grade, in AZ55 bare or AZ50 painted coating. Optional gauges are 24 gauge and 26 gauge ASTM A792 steel, a 50 ksi grade, also in AZ55 bare or AZ50 painted coating.

The manufacturer's current product page lists the substrate options as 26 gauge and 29 gauge Galvalume, and 29 gauge G-100 painted steel.

• Acrylic-coated Galvalume, sold as Galvalume Plus.
• Fluoropolymer finish based on Kynar 500 PVDF resin.
• Silicone modified polyester, with siliconized polyester and polyester also named.

McElroy Metal stocks 29 gauge Kynar 500 colors.

The painted substrate is 29 gauge G-100 steel. The 29 gauge Kynar 500 colors are stocked, and color charts are published for Max-Rib, along with 3D texture samples of McElroy panels.

Max-Rib is an exposed-fastener wall and roof panel used on slopes down to 1:12. Tape sealant is required in the side laps on slopes from 3:12 down to 1:12. At 3:12 and steeper, the panel is used without sealant.

The installation substrate is plywood or purlins, described on the current page as solid deck or open framing. The profile drawing gives a fastener pattern at eaves, ridges and endlaps, and a separate fastener pattern at intermediate purlins.

Oil canning is inherent in all metal panels.

• Minimum slope with sealant: 1:12
• Minimum slope without sealant: 3:12
• Install substrate: solid deck or open framing

• Uplift: UL 580 Class 90.
• Impact: UL 2218 Class 4.
• Fire resistance: UL 263 and UL 790 Class A.
• Florida Product Approval: FL 1747.2 and FL 1832.3.
• Windstorm listing RC-157.
• TDI listing over a plywood deck.

The testing and approvals are product specific, and not every item applies to all widths and gauges.