Low-E™ Therma-Sheet

An ICC-ES certified stand-alone roofing underlayment.

Low-E™ Therma-Sheet Insulation has always offered the benefits of Low-E™ – an industry-leading thermal and moisture barrier - to the roofing industry. Now, Therma-Sheet has earned certification by the International Code Council Evaluation Service (ICC-ES), meaning Therma-Sheet meets all requirements of a stand-alone roofing underlayment for the building industry. Because Therma-Sheet can now be used as a single underlayment product rather than part of a "sandwich" of products, it offers a more affordable means of energy efficiency to homeowners and reduces installation time and required materials.

About Low-E™ Therma-Sheet

Therma-Sheet is a 99% pure polished aluminum facing heat laminated to a closed cell foam core. It provides excellent thermal and moisture protection under metal roofing, stone coated steel, clay tile and composite shingles. With an airspace beneath metal roofing, Therma-Sheet reflects 97% of radiant heat. Without an airspace beneath composite shingles, Therma-Sheet provides an excellent thermal break that, without reflectivity, still lowers the temperature below your roof deck 8-12 degrees. Therma-Sheet reflects up to 97% of the radiant heat that is normally transferred into the attic by super-heated roofing materials, significantly reducing attic heat gain. Conversely, Therma-Sheet prevents heat loss through the attic during colder months, all of which reduces heating and cooling costs for homeowners.

Some of Therma-Sheet’s other benefits include:

  • Faster installation: Roofing contractors only need to install one underlayment product, keeping labor costs low.
  • Versatility: Therma-Sheet is available in both 1/4” and 1/8” thicknesses, and provides an excellent thermal and moisture barrier under metal roofing, stone coated steel, concrete, clay tile, composite shingles and more.
  • Lightweight: 500 square feet weighs just 18 lbs.
  • Easy to handle:Therma-Sheet is flexible, non-toxic and easy to cut and install.
  • Seals around fasteners: Provides a more thorough vapor and moisture barrier.
  • Durable: Can be left exposed when "drying out" time is needed.
  • Separate from the pack: Offers an efficient, affordable energy upgrade to roofing systems that most products are unable to match.
  • Aids in Design Can be used as an alternative in cool roof design.


    PRODUCT NAME: Low-E™ Therma-Sheet

  • PRODUCT DIMENSIONS & DESCRIPTIONS: Double-sided scrimmed aluminum foil laminated to polyethylene foam (1/8”, 7/32”).
  • WIDTH: 4’ LENGTH: 125’ (standard with 4” overlapping flange)
  • R-VALUE: R-9 downward heat flow only (With 1.5” airspace)
  • CORE MATERIAL: Polyethylene
  • FACING: 99.4% Polished Aluminum
  • PERM RATING: ASTM E - 96 0.008/li>
  • EMITTANCE: ASTM C-1371 0.03



Why Low-E™?

Green building is not just a trend, but the wave of the future as more and more homeowners and builders demand energy efficient homes and products. Low-E™ Insulation products are designed for maximum energy and cost efficiency. Whether it's under slab, under roof, around duct work or wrapping the entire house, Low-E™ Reflective Insulation saves more money on heating and cooling than regular insulation and housewrap.