Letters

SPRI supports revised standard

On behalf of the single-ply roofing industry, I am writing to comment on "Issues with TPO membranes" by Mark S. Graham, NRCA's associate executive director of technical services, August issue, page 24.

SPRI recognizes there are recent reports of and articles referring to differences in the performance of various TPO membranes evaluated under ASTM D6878, "Standard Specification for Thermoplastic Polyolefin Based Sheet Roofing." SPRI remains fully in support of increasing the standard's performance requirements so concerns about the viability of TPO membranes can be put to rest once and for all.

SPRI understands an ASTM International task group addressing this issue has work in progress, which is necessary to support a revised standard. To this end, SPRI supports ASTM International's commitment to strengthen the current standard based on sound research.

The article you published provides a special service to the industry. It reminds those who make decisions about purchasing any roof membrane that they must confirm the specific system being purchased will perform with the specific building conditions regardless of roof system type.

TPO membranes have been available and successfully performing in roofing applications since the early 1990s. During the past five years alone, more than 4 billion square feet of TPO roof membranes have been sold in North America; nearly the entirety of those have performed without issue. SPRI is confident TPO roof systems will continue to provide quality and value for many years to come.

Mike Ennis
SPRI
Waltham, Mass.

Graham responds: Thank you for your letter. NRCA looks forward to SPRI's support in making meaningful improvements to ASTM D6878.