S-5! RibBracket for R-Panel & PBR Metal Roofs: Engineering and Sizing Guide

Key Takeaways

• S-5! RibBracket is engineered specifically for North American trapezoidal R-Panel and PBR-Panel exposed-fastened metal roof profiles.
• Features a slotted top hole accommodating standard M8 nuts and bolts to simplify array alignment and ancillary mounting.
• Attached to sheeting crowns using stainless-capped piercing screws or Bulb-Tite rivets with factory EPDM gasket reservoirs.
• Never install on panel lapped ribs, and never use RibBracket for snow retention systems, which require direct purlin attachment.

What Is S-5! RibBracket?

The RibBracket is engineered to Mount HVAC, Solar PV, and More Onto Common North American Exposed-Fastened, Trapezoidal-Rib Roof Profiles. Across commercial and agricultural facilities in the United States, trapezoidal metal roofing is dominated by two profiles: R-Panel and PBR-Panel. Both profiles feature major ribs spaced 12 inches on center, standing 1-1/4 inches high with sloping sidewalls and intermediate stiffening ribs.

The RibBracket is the perfect attachment solution for specific North American trapezoidal, exposed-fastened metal roofs.These profiles are commonly referred to as R-Panel or PBR-Panel. Unlike generic flat L-feet that sit in the drainage valley where water collects, RibBracket is an engineered aluminum casting that straddles the major rib crown, raising roof penetrations high above water flow lines.

With RibBracket, installers can Mount HVAC, walkways, railed PV systems and more to your metal roof. You can also pair this metal roof bracket with the S-5-PVKIT® for rail-less (direct-attach™) solar PV mounting. When additional height is desired with the S-5-PVKIT, use RibBracket III. Review solar-panels-on-a-metal-roof and address do-solar-panels-damage-your-roof concerns before designing array layouts.

Slotted Top Hole and Alignment Adjustability

Rooftop solar installation on trapezoidal panels often suffers from minor purlin waviness or panel drift across long bays. If an attachment bracket provides only a round bolt hole, misalignments cannot be corrected without straining panel frames.

The RibBracket features a slotted top hole, which accommodates standard M8 nuts and bolts, simplifies alignment and maximizes adjustability in attaching ancillaries.

This slotted geometry provides several key installation benefits:

• Lateral Tolerance: Installers can shift rail hardware or PVKIT grab brackets laterally to accommodate slight manufacturing variations in trapezoidal panel widths.
• Hardware Standardization: Standardizing on M8 metric hardware allows installers to use the same sockets and torque wrenches across brackets, clamps, and grounding lugs.
• Multi-Ancillary Support: In addition to solar PV, the slotted channel provides mounting points for electrical conduit clamps, wire management trays, and rooftop walkways.

Sheeting-Only Attachment and Fastener Rules

RibBracket is mounted directly onto the crown of the trapezoidal sheet using stainless-capped piercing screws (provided) or Bulb-Tite rivets (not provided) . The sheeting-only attachment eliminates the need to locate and hit underlying structural purlins with every solar foot.

However, sheeting-only mounting requires strict adherence to structural boundaries:

1. Fasten Only to Panel Crowns: Screws must penetrate the flat top crown of the major rib. Fastening into the rib sidewalls can induce shearing tear-out under wind uplift forces.
2. Verify Metal Gauge: Ensure panel steel is 26-gauge or 24-gauge. On thinner 29-gauge agricultural sheeting, installers should use Bulb-Tite rivets to expand pullout resistance.
3. Lapped Rib Prohibition: Due to variations in lapped ribs and sealant placement, installing these brackets on a lapped rib of trapezoidal panels should be avoided. Panel laps contain factory butyl mastic tape; driving screws through lap joints risks compromising the weather seal between adjacent sheets.
4. No Snow Guard Mounting: No. RibBracket is a sheeting-only attachment for face-attached metal roof profiles. Snow guards on these types of profiles should always be attached to the structural purlins. Snow sliding forces accumulate immense shear loads that will rip sheeting-only brackets off the roof.

For high-wind installation details, compare structural engineering in florida-hurricane-resilient-solar-and-wind-load-guide and railed methods in ironridge-xr-rails-buying-guide-us.

Integrated EPDM Reservoir Weatherproofing

With the RibBracket, there are no messy sealants to apply. The factory-applied, EPDM rubber gasket weatherproofs and makes installation easy. The reservoir conceals EPDM from UV exposure, preventing drying and cracking.

S-5! brackets feature integrated sealant reservoirs to prevent over-compression of the seal and to protect the sealant from UV degradation. No risky, field applied sealants are ever used.

When screws are driven through the bracket base, the internal reservoir ensures uniform gasket compression without extrusion, forming a permanent barrier against water ingress. Installation requires minimal effort: No surface preparation is necessary. Simply wipe away excess oil and debris, align and apply.

Step-by-Step Installation Process

1. Map Rib Layout: Identify clean, unlapped intermediate trapezoidal ribs spaced across the solar array footprint.
2. Clean Surface: Wipe away dust, loose dirt, and manufacturing oils from the rib crown.
3. Position RibBracket: Straddle the bracket over the major rib crown, verifying that the bracket legs seat squarely on both shoulders.
4. Drive Piercing Screws: Using a clutch-controlled drill, drive the provided stainless-capped screws through the pre-punched holes into the sheet crown until the bracket firmly seats.
5. Mount PV Hardware: Insert an M8 bolt through the slotted top hole. Secure the S-5! PVKIT grab bracket or rail L-foot and torque to manufacturer specifications.

Safety and Structural Precautions

• Purlin Load Verification: While RibBracket attaches to sheeting alone, the accumulated weight of the array must be supported by the building's secondary structural framing. Confirm purlin capacity for total dead and live loads.
• Slip and Fall Prevention: R-panel metal roofs are slick, especially on pitches above 2:12. Always utilize OSHA-compliant fall arrest systems tied off to certified structural anchor points. Never tie off to RibBrackets or panel sheeting.
• Sharp Metal Debris: Drilling self-piercing screws creates metal swarf (shavings). Sweep shavings immediately after driving screws; loose metal filings rust rapidly and stain metal roof coatings.

When to Consult a Structural Engineer

• Wind Speed Above 130 MPH: High-wind zones require calculating tributary uplift areas per bracket to determine if additional mounting rows are necessary.
• Light-Gauge 29-Gauge Metal: Agricultural grade metal requires pullout testing to ensure sheeting-only screws meet safety factors.