Performance Data
Never Re-Roof Again.®
Energy Star–qualified solar reflectance and thermal emittance values for Interlock aluminum metal roofing — cool-roof performance data by color and profile.
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This document is part of the roofbook.com library — the official, primary-source document library for Interlock metal roofing. It is published by Interlock Metal Roofing Systems. Learn more at https://www.interlockroofing.com.
It is the ENERGY STAR Roof Product List entry for Interlock Roofing Ltd., listing the qualified Alunar-coated metal roofing models — across the Shake, Shingle, Slate, Standing Seam and Tile profiles — with their initial solar reflectance, solar reflectance after 3 years, and initial emissivity (emittance) by color. The data lets specifiers document cool-roof performance for energy codes and credits.
Reflectance varies by color: most darker Alunar colors fall around 0.25–0.28 initial solar reflectance, mid-tone greys reach about 0.37, and the highest listed value is Aged Copper Penny at 0.55 initial (0.35 after 3 years). Initial emissivity is 0.84 across the listed models. These values support cool-roof and ENERGY STAR qualification, with reflectance affecting attic heat gain and cooling demand.
The listed Interlock metal roofing models are qualified as steep-slope (Steep Slope? = Yes) ENERGY STAR products and are not qualified as low-slope products. This reflects their use as a sloped residential roof covering rather than a flat/low-slope membrane.
The ENERGY STAR list shows a 40-year warranty period for the Interlock models. The list also carries a standard note that the warranty does not necessarily cover solar reflectance — reflectance and emittance are performance values, not warranty terms, so the roof's material warranty should be reviewed separately in the Guardian Warranty document.
ENERGY STAR records both the initial reflectance and the value after 3 years of weathering because real-world performance drops as a surface ages and soils. For example, Aged Copper Penny starts at 0.55 and settles near 0.35, while darker colors hold closer to their initial 0.24–0.25. The list also notes that, as of December 31, 2007, qualified products may not be cleaned during testing, so the aged value reflects untouched weathering.
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ENERGY STAR Roof Product List List Posted on July 18, 2012 Below are currently qualified ENERGY STAR models available for sale in the U.S. *As of December 31, 2007, all new ENERGY STAR qualified products are prohibited from being cleaned during testing. **Warranty does not necessarily cover solar reflectance. Company Name Brand Model Type Initial Solar Reflectance Solar Reflectance after 3 years Initial Emissivity Low Slope? Steep Slope? Roof Cleaned Prior to 3rd Year Test* Warranty Period (Years)** Interlock Roofing Ltd. Shake Alunar Aged Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Aged Copper Penny Metal 0.55 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Black Metal 0.25 0.24 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Brown Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Charcoal Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Dark Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Royal Blue Metal 0.29 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Tile Red Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Weathered Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shake Alunar Weathered Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Aged Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Aged Copper Penny Metal 0.55 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Black Metal 0.25 0.24 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Blue Metal 0.33 0.32 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Brown Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Charcoal Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Commercial Red Metal 0.40 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Dark Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Forest Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Royal Blue Metal 0.29 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Tile Red Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Weathered Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Shingle Alunar Weathered Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Aged Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Aged Copper Penny Metal 0.55 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Black Metal 0.25 0.24 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Blue Metal 0.33 0.32 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Brown Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Charcoal Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Commercial Red Metal 0.40 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Dark Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Forest Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Royal Blue Metal 0.29 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Tile Red Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Weathered Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Slate Alunar Weathered Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Aged Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Aged Copper Penny Metal 0.55 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Black Metal 0.25 0.24 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Blue Metal 0.33 0.32 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Brown Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Charcoal Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Commercial Red Metal 0.40 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Dark Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Forest Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Royal Blue Metal 0.29 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Tile Red Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Weathered Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Standing Seam Alunar Weathered Grey Metal 0.37 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Aged Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Aged Copper Penny Metal 0.55 0.35 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Black Metal 0.25 0.24 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Brown Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Charcoal Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Dark Green Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Royal Blue Metal 0.29 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Tile Red Metal 0.26 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Weathered Brown Metal 0.28 0.25 0.84 No Yes N 40 Interlock Roofing Ltd. Tile Alunar Weathered Grey Metal 0.37 0.35 0.84 No Yes N 40