Corrugated & R-Panel Exposed-Fastener Metal Roof Solar Mounting Guide
Corrugated wavy metal, Ag-panel, and trapezoidal R-panel roofs don't have vertical standing seams to clamp onto. To prevent leaks, attachments must straddle the HIGH CROWN of the rib (where water sheds away)—never in the flat valley where stormwater rivers flow.
Cross-Sectional Roof Attachment & Flashing Schematic
Torque & Fastener Spec: 1/4'' Self-Drilling Sheet-Metal Screws into High Rib Crown OR Structural Purlin Bolt
[S-5! CorruBracket / RibBracket Mounted on HIGH CROWN]
|======| |======|
| EPDM | | |
________________| |__________________| |________________ <-- Water Flows in Low Valley
========================================================================== <-- Purlin / Roof Deck✅ Roof Warranty Protection Checklist (GAF / Owens Corning / Metal)
- ✓All solar brackets (S-5! CorruBracket or RibBracket) MUST mount on the top crest of the trapezoid or sinusoidal wave—never in the low water-drainage trough.
- ✓Before laying solar panels over an older exposed-fastener metal roof, replace all aging 15-year-old #10 wood screws in the array footprint with oversized #12/#14 stainless steel EPDM-washer screws.
🚩 Subcontractor & Salesperson Red Flags
- ✕Installer bolts L-feet directly into the flat bottom valley of an R-panel or Ag-panel roof.
Step-by-Step Mounting Protocol & Engineering FAQs
🛠️ MOUNTING STEP1. Replace Existing Exposed Roof Screws Under Array
Swap out any sun-baked neoprene roof screws under the solar footprint with lifetime stainless cap screws before covering them with panels.
🛠️ MOUNTING STEP2. Compress EPDM Gasket on High Rib Crest
Fasten S-5! RibBracket or CorruBracket into the sides/top of the high rib crown until a slight visual bulge appears in the virgin EPDM gasket.
❓ ROOFER FAQWhy should I replace the existing roof screws before putting solar on an R-panel roof?
Standard painted roof screws have rubber washers that dry out after 15–20 years. Upgrading the screws underneath the solar footprint to lifetime stainless-capped EPDM screws costs only $150 and prevents ever having to unbolt the panels to fix a screw washer.
Explore Other Roof Mounting Blueprints
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