Definition
Ballasted racking is a flat-roof solar mounting system that uses weighted ballast blocks (typically concrete) to resist wind uplift instead of roof penetrations. Common on TPO/EPDM commercial rooftops to preserve roof warranty.
Key Takeaways
- Ballasted racking = non-penetrating flat-roof solar.
- Concrete or steel weights resist wind uplift.
- Pros: no penetrations, fast install. Cons: structural capacity needed.
- Not suitable for HVHZ (high-wind zones).
- ASCE 7-22 wind analysis required for ballast sizing.
Frequently Asked Questions
4 commonly searched questions about Ballasted Racking.
What is ballasted racking?
Non-penetrating flat-roof solar mounting using concrete or steel ballast blocks for wind resistance. Common on commercial TPO/EPDM rooftops.
Pros and cons?
Pros: no roof penetrations, preserves warranty, faster install. Cons: requires structural capacity for ballast (typically 4–8 psf), limits tilt angle (typically ≤10°), not allowed in high-wind zones (HVHZ).
How is ballast sized?
Per ASCE 7-22 wind uplift analysis. Site-specific wind speed, tilt, GCp coefficients, roof zones. Typical 3–10 psf for low-wind sites; can't be used in HVHZ.
Major brands?
Unirac SunFrame, IronRidge BX-System, Schletter Carolina, RBI Solar, K2 Systems.
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