GAF EverGuard TPO and EverGuard Extreme GreenSpec

Pre-consumer (also called post-industrial ) recycling refers to the reuse of industrial by-products, as distinguished from material that has been in consumer use. The iron-ore slag used to make mineral wool insulation and the fly ash used to make concrete are examples of post-industrial recycled materials. While post-consumer recycled content is preferable, a product that uses pre-consumer content or recycles a seldom-used waste product, especially in an area where recycled products are hard to find, can be considered green.

Some materials provide a better alternative in an application dominated by products for which there are concerns about toxic constituents, intermediaries, or by-products. With the panoply of products made with polyvinyl chloride (PVC) and brominated flame retardants, some products are green simply because they provide an alternative. Examples of this are natural wall coverings, drain and vent piping, and roofing membranes. Some green products are free of hazards common to the product category; for example, LED lighting is inherently free of the mercury found in fluorescent lighting sources.

Tristan Roberts

Editorial Director

Single-ply roofing membranes, typically used on large commercial buildings, are also occasionally used on homes and light-commercial buildings for low-slope roof areas and beneath upper-floor walk-out decks. TPO has recently replaced PVC as the most common thermoplastic membrane material.

Durability is the first priority for roofing membranes membrane replacement or repairing an interior after roof failure wastes material, time, and money. However, there is no clear method of measuring a roofs service life, and quality system design and detailing, construction quality control, and maintenance (as opposed to repair) may have as much to do with a roofs durability as does membrane selection.

  • GreenSpec lists best-in-class TPO membranes from companies that support enhanced heat testing, and show proactive attention to performance.

Other key considerations include reflectivity, recyclability, and the environmental and toxicity profile of the material and its manufacture.

A cool roofs effectiveness, as measured by solar reflectance index (SRI ), declines over time. Focus on three-year aged SRI values rather than initial SRI values.

  • Listed products have high initial and three-year SRI values.

Different membrane materials contain different chemical compositions of varying toxicity. Studies have found that roofs contribute a range of hazards to rainfall runoffhowever, product-specific leaching data is not available. TPO is an inherently cleaner polymer than PVC and contains far fewer potentially problematic additives. Known TPO manufacturing methods do not raise toxicity concerns comparable to those of PVC. TPO may contain problematic UV stabilizers, however most TPO formulations today don’t include halogenated flame retardants and biocides.

  • Listed TPO products do not, to our knowledge, use biocides or halogenated flame retardants.
  • GreenSpec doesnt list PVC membraneshowever, GreenSpec would consider listing a best-in-class PVC product where the manufacturer could demonstrate dramatically reduced life cycle impacts and low leaching relative to an industry norm, along with high performance in other areas (recycling, reflectivity, service life).

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