Cool roof proposals: compare measured properties and the whole assembly

Turn the cool-roof claim into a product question

Ask the provider to identify the exact product and where its rated data can be checked. The Cool Roof Rating Council explains that cool roofs use high solar reflectance and thermal emittance, and that color alone does not determine performance.

Keep the manufacturer name, product line, color or blend, rating record and proposal revision together. A general label such as cool, reflective or energy-saving is not a substitute for the proposed product's documentation.

Compare the reported properties on the same basis

Ask which values are being compared: solar reflectance, thermal emittance or a combined solar reflectance index. Confirm whether each value is initial or aged, because the rating directory can report both.

Do not combine unlike metrics into a homemade score. Use the same property, test basis and aging condition for each option, and ask the provider to explain any missing value instead of estimating it.

Put climate and roof slope into the recommendation

The council notes that climate affects potential benefits and that winter heating tradeoffs can matter in colder regions. Ask what local cooling and heating assumptions support the recommendation and whether the roof is low-slope or steep-slope.

Treat those answers as proposal assumptions, not guaranteed savings. The Department of Energy describes reflective asphalt shingles as one option that can reduce solar heat gain, particularly in warmer climates, but an individual home's result depends on more than the surface product.

Keep the rest of the roof assembly in view

Compare deck repairs, underlayment, flashing, ventilation, drainage, fastening, warranty terms and code requirements alongside surface ratings. A reflective product does not resolve an incomplete installation scope.

Before signing, record the selected product and alternatives considered, who confirmed compatibility, and what would trigger a substitution. Recheck the delivered product identifiers during closeout without climbing onto the roof.

Related guides

• Choose roofing materials by constraints, not a single 'best' label
• Roof and attic ventilation: questions before changing the system
• Roof replacement and solar: coordinate the scopes before either crew starts