CSLB C-39 Roofing ContractorFlashing, Ventilation and InsulationEasy
Under California's Title 24 Energy Code, a new low-slope (steep-slope alternative) residential roof covering must meet minimum cool roof requirements. What is the minimum aged solar reflectance typically required for steep-slope residential roofing products under the current standard?
- A0.40
- B0.63
- C0.10
- D0.20
Show answer & explanationAnswer & explanation
Correct answer: D. 0.20
Title 24 sets a minimum aged solar reflectance of 0.20 (along with a minimum thermal emittance of 0.75, or an equivalent SRI of 16) for steep-slope residential roofing products to reduce heat gain and energy use.
Why the other options are wrong
- A. Exceeds the minimum; this level applies to some low-slope categories instead.
- B. This value is far above the residential steep-slope minimum requirement.
- C. Below the code minimum reflectance threshold.
Title 24 Cool Roof Requirement
California Title 24 requires steep-slope residential roofing to meet a minimum aged solar reflectance of 0.20 and thermal emittance of 0.75 (or SRI 16) to qualify as a cool roof.
- Applies primarily to new construction and reroofing in most climate zones.
- Low-slope roofs have higher reflectance requirements than steep-slope.
- Reduces urban heat island effect and cooling energy demand.
Memory trick: 'Point-two-oh keeps the cool roof aglow.'