CSLB C-39 Roofing ContractorLow-Slope RoofingEasy

A client wants a single-ply membrane that reflects sunlight to reduce cooling costs and is typically manufactured in white sheets, unlike EPDM which is almost always black. Which membrane best fits this description?

  1. ABuilt-up roofing (BUR)
  2. BEPDM
  3. CTPO
  4. DModified bitumen (SBS)
Show answer & explanation

Correct answer: C. TPO

TPO (thermoplastic polyolefin) is most commonly manufactured in white or light colors for high solar reflectance, making it a popular choice for cool-roof applications, whereas EPDM is typically black.

Why the other options are wrong

  • A. BUR is a built-up system, not a reflective single-ply sheet membrane.
  • B. EPDM is generally black and absorbs heat rather than reflecting it.
  • D. Modified bitumen is asphalt-based and typically dark, not reflective by default.

TPO Membrane

Thermoplastic polyolefin single-ply membrane, typically white, known for reflectivity, heat-weldable seams, and energy efficiency.

  • Usually white for solar reflectance
  • Seams are hot-air welded
  • Popular for cool-roof compliance

Memory trick: TPO is 'the pale option' — white and reflective.

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