PBR represents purlin bearing R panel. So, there is an extensive overlap section, which provides coverage for the subsequent panel. It creates a connection between metals. Your metal roofing panels will have a stronger and longer-lasting connection.
A purlin-bearing leg overlaps between your metal roof panels to prevent the effects of wind and moisture. Roofing professionals install the panels on an open framing (like wooden beams and metal purlins).
An R-panel involves an exposed fastener as corrugated panels. So, you can use R panels for roof and metal wall panels. Originally, R-panel had applications in pre-fabricated metal buildings. But, these panels have several other applications today, including Shouses, Shows, and Barndominiums.