Introduction
Flat tile roofs (concrete or clay) are among the most common roofing types for residential solar installations. They also present unique challenges: tiles are fragile, heavy, and must maintain their water-shedding function. The hook-based mounting system-using stainless steel hooks anchored directly to roof rafters-is the industry's proven solution.
At LongsunGreen, we manufacture high-quality solar mounting structures designed for these exact applications. This guide delivers practical, step-by-step instructions for professional installers.
Why Hook-Based Systems?
| Feature | Benefit |
|---|---|
| Direct rafter attachment | Superior wind/snow load resistance |
| Tiles are replaced, not discarded | Preserves roof integrity |
| Stainless steel components | Decades of corrosion resistance |
| Positive mechanical fastening | Long-term reliability |
Step-by-Step Installation
Phase 1: Preparation
Inspect structure: Verify rafters are sound and free from rot
Identify tile type: Flat, curved, or "S" profiles require different hook designs
Calculate loads: Confirm roof can support additional PV system weight
Phase 2: Tools Required
Electric drill, socket attachment, tape measure, spirit level, tile pry bar, torque wrench. Safety gear: helmet, gloves, harness.
Phase 3: Hook Installation
Mark rafter positions accurately on the roof
Lift and remove tiles gently using a pry bar to avoid breakage
Install hooks over rafters using self-tapping screws (e.g., ST6.3*80)
Apply sealant in pilot holes for extra waterproofing
Modify and replace tiles: Cut a small notch for the hook arm, then reinstall tiles flat
Phase 4: Rail Installation
Attach aluminum rails to hooks using M8*25 bolts and T-nuts
Use rail connectors if splicing is needed for longer rows
Phase 5: Panel Installation
Place first panel on rails, flush with rail ends
Secure with end clamps (row ends) and mid clamps (between panels)
Critical: Include grounding sheets with every mid-clamp for NEC-compliant bonding
Work systematically: bottom to top, left to right
Phase 6: Final Verification
Verify torque on all fasteners
Inspect tile seating and panel alignment
Confirm electrical grounding before commissioning
Common Mistakes to Avoid
| Mistake | Prevention |
|---|---|
| Wrong hook for tile type | Match profile to tile |
| Over-tightening screws | Use torque wrench |
| Insufficient sealant | Apply liberally at penetrations |
| Missing grounding sheets | Install with every mid-clamp |
Why Longsun Green?
Materials: AL6005-T5 aluminum + SUS304 stainless steel for corrosion resistance
Performance: Withstands 60 m/s wind and 1.6 kN/m² snow loads
Certification: ISO 9001-compliant manufacturing
Global supply: Daily shipments of 8,000+ units worldwide
Conclusion
Hook-based mounting on flat tile roofs delivers secure, code-compliant PV installations that last decades. By following these steps and using quality components, installers ensure both system longevity and customer satisfaction.
About Longsun Green
Leading manufacturer of solar mounting structures, serving global markets with reliable products and engineering expertise.
