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Base and Ply Sheets

HPR® Glasfelt

  • Designed for Today's Demanding Roofing Needs
  • A Better Roofing Felt
  • Rot-Proof Protection

HPR Glasfelts are heavy-duty, asphalt-saturated fiberglass mats used as ply sheets in the construction of high-performance built-up roofs. They are also used to construct and maintain built-up roofing and membrane waterproofing systems. The mat is made of fiberglass monofilaments bonded with a water-resistant melamine binder and reinforced with fiberglass strands. It is coated with high-quality, roofing-grade asphalt and dusted with fine sand to prevent sticking. The asphalt-impregnated glass mat shall neither crack nor be so sticky as to cause tearing upon being unrolled at ambient temperatures of about 50°F (10°C). HPR Glasfelt meets and exceeds ASTM D 2178 and Type IV.

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Product Specifications


Quality Control Feature Photo

Designed for Today's Demanding Roofing Needs

Today, roofs are larger and flatter. The incidence of thermal shock damage has increased because of the popularity of lightweight metal decks, sophisticated heating and air conditioning systems, and increased insulation. As modern engineering practices have imposed greater demands upon roof system performance, the quality of conventional roofing paper has deteriorated. HPR Glasfelts put an end to the "quality slide." They have the strength and flexibility to meet today's more demanding requirements. 

Article Photos-Batch 6

A Better Roofing Felt

HPR Glasfelts, by nature of the manufacturing process, are uniformly porous. Interply asphalt moppings readily penetrate adjacent felt layers to ensure continuous ply adhesion. In addition, the felt's natural porosity minimizes the negative effects of trapped moisture and blistering. 

Product Page Feature Photos

Inorganic, Rot-Proof Protection

HPR Glasfelts are inorganic, rot-proof roofing felts. They will not wick or absorb moisture. As a result, the risk of felt ply delamination is minimized, and a stronger, more secure roof assembly is produced. 

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RMer Span Curve Panels are being installed onto the North County Regional Library