CSLB C-39 Roofing ContractorFlashing, Ventilation and InsulationHard
California's Title 24 cool roof requirements reference 'aged' solar reflectance values rather than initial (as-installed) values. Per Cool Roof Rating Council (CRRC) protocols, over what exposure period is this aged reflectance value determined?
- A1 year
- B10 years
- C3 years
- D30 days
Show answer & explanationAnswer & explanation
Correct answer: C. 3 years
CRRC rating protocols require roofing products to be weathered for 3 years to determine the 'aged' solar reflectance value, which accounts for dirt accumulation and material degradation over time — a more realistic long-term performance measure than the initial reflectance value.
Why the other options are wrong
- A. 1 year does not match the CRRC standard exposure period.
- B. 10 years exceeds the CRRC testing protocol duration.
- D. 30 days is far too short to represent realistic long-term weathering.
Aged Solar Reflectance (CRRC)
The reflectance value of a roofing product after 3 years of natural weathering exposure, used by Title 24 as the compliance benchmark instead of initial reflectance.
- CRRC standard weathering period is 3 years
- Aged values account for dirt/soiling reducing reflectance
- Title 24 compliance is based on aged, not initial, values
Memory trick: Three years of dirt and sun tell the real reflectance story.