Multi-Rib is McElroy’s proprietary version of the industry’s standard R-Panel and is a multi-use roof and wall panel primarily used in pre-engineered metal building applications. An optional Purlin Bearing Leg (PBR) rests on purlins and provides support for fastening the panel lap.


  • Minimum slope: 1:12 (with sealant)
  • Multi-Rib is also available with MoistureLok

  • Oil Canning is a natural occurrence in metal panels and is not a cause for panel rejection

Testing Data

  • Fire Rating: Class A
  • Uplift Test: UL580 Class 90
    ASTM E1592 (26 GA PBR Only)
  • Air Infiltration:  ASTM E1680
  • Water Infiltration: ASTM E1646
  • Class 4 Impact Resistance: UL2218
  • Florida State Approval:
    1747.8, 1832.10
  • Fire Resistance: UL263
  • Texas Department of Insurance Approval: Evaluation RC-63 and

  • For any available Test Data, Section Properties or Load Tables, please visit our downloads section

Panel Options

  • Roof panels:
    urlin bearing leg required
  • Wall panels:
    non-purlin bearing leg optional
  • Coating:
    - Kynar 500® (PVDF)
    Silicone Modified Polyester (SMP)
  • Substrate:
    - Standard 26 GA Galvalume® 
      (roof and wall panels)

    - Optional 24, 22 GA Galvalume  
      (wall panels)