Letters

Professional Roofing welcomes letters to the editor. Views expressed in "Letters" are not necessarily those of NRCA. Letters must be signed and include a return address and telephone number. Professional Roofing reserves the right to edit letters for clarity and length. Send letters to Ambika Puniani, Editor, Professional Roofing, 10255 W. Higgins Road, Suite 600, Rosemont, IL 60018-5607; fax (847) 299-1183; or e-mail apuniani@nrca.net.

TPOs in Europe

I read the article "TPOs—commodity or specialty?" June issue, page 38, with much interest. Overall, I think the author, Stephen A. Sharp, owner of Sharp Roofing Associates Inc., Ironia, N.J., does a nice job explaining the TPO situation in the United States.

I think your readers would be interested to know that in Europe, where flexible polyolefin (TPO in the United States) first was used as roof and waterproofing membranes, the situation is quite different.

The average flexible polyolefin membrane in Europe is 0.064 inches (1.6 mm [63 mils]) thick. One manufacturer uses fiberglass reinforcement in addition to polyester reinforcement to improve dimensional stability. At least one manufacturer has determined that solvent wiping of seams is necessary before welding—even with new material—to achieve consistent seaming.

Flexible polyolefins for roofing were introduced in Europe in 1991. They quickly grew in popularity for four years to five years—just as they have in the United States. Since then, their growth stalled primarily because of what contractors perceive as problems with seam consistency and detailing. It is estimated that, in Europe, the polymeric single-ply market share breaks down as follows: PVC—66 percent; EPDM—10 percent; EVA/CPE—10 percent; TPO—9 percent; and PIB—5 percent. PVC single-ply usage grew almost 5 percent during 2001 in Germany.

We at Sarnafil believe Sharp gives too much credit to TPO membranes for environmental benefits. PVC roof membranes take the same or less energy to produce as TPO membranes. Certain PVC manufacturers have specialized production equipment that results in 100 percent yield. Any waste or trimmings are recycled into the membrane. The biggest factor in the environmental equation is life expectancy. There are certain PVC roof systems that have lasted as long as 40 years. As Sharp points out, there are TPO roof systems being replaced at 4 years to 8 years of age. How can there be any environmental benefits of TPO if the life expectancy is unknown?

Brian J. Whelan
Sarnafil Inc.
Canton, Mass.

Following is Sharp's reply to the letter:

"Thank you for your letter.

"One problem from my perspective is that, in general, the ‘European experience' does not translate well to the U.S. roofing industry reality. EPDM is clear evidence of this. Most roofing contractors, building owners and designers want verifiable U.S. experience regarding roof system performance. And, like it or not, U.S. roofing professionals' expectations, perceived needs and construction methods are quite different from European ones.

"As for your comments regarding TPOs' environmental aspects, with regard to environmental legislation and mandates, the United States has been ahead of Europe in many areas, such as unleaded fuel use and asbestos- and lead-containing building materials. TPOs' environmental benefits will pan out based on numerous factors, not just the energy needed to manufacture a roof membrane. There still is much debate and disagreement among experts regarding the environmental pros and cons of many products—not just PVCs and TPOs.

"Finally, most TPOs are not failing in four years to eight years. I am confident responsible TPO manufacturers will continue to determine what their products can and cannot achieve. I believe a greater challenge at this point may be maintenance of the product."

FM Global responds

We at FM Global were quite puzzled to read the article "Where is FM Global headed?" May issue, page 20, by Dick Baxter, president of CRS Inc., Monroe, N.C. Who better to answer that question than FM Global?

Although Baxter certainly is entitled to his views, his article contains much speculation, oversimplification and inaccuracies about our company's products and services.

Had Professional Roofing called us to fact check the article, we believe it would have resulted in more balanced coverage for your readers' benefit.

It is tempting to write a long letter with statistics and anecdotes to counter every inaccurate point made in Baxter's article. However, we'll simply address the article's overall theme, which attacks the soundness of FM Global's roofing-related engineering recommendations and competence as they relate to roofing expertise.

Baxter attempts to paint a picture of FM Global as a company out of step with the roofing industry; we believe nothing could be further from the truth.

As you may know, the centerpiece of the FM Global organization is a mutual insurance company (owned by its policyholders) with more than 167 years of property engineering experience and a team of more than 1,200 engineers worldwide. FM Global's average engineer has been with our organization for more than 10 years, and our employee turnover rate is among the lowest in any engineering profession.

Roofing-related problems continue to contribute to sizable property losses, and helping our policyholders prevent losses from occurring is central to the values we deliver.

One way we do this is by "independently" testing the performances of thousands of products and services and approving only those that meet FM Approvals' rigorous property loss-prevention standards. Many products submitted for testing and approval fail to meet our standards. However, manufacturers know if their products earn FM Approvals ratings, the approvals communicate to their customers that a product has been tested for real-world conditions and will perform as intended when properly installed.

The converse also is true: A product is unlikely to perform properly if improperly installed. For example, an engineering analysis we did of Hurricane Andrew-related losses revealed a startling fact: Nearly 60 percent of roofing and other structural losses could be attributed to human factors. Hurricane Georges, which hit Puerto Rico in September 1998, validated the soundness of those findings. Those who followed FM Global's recommendations and used properly installed FM-approved products suffered losses that were 75 percent to 80 percent smaller than those property owners who did not.

Although FM Global does not intend to ensure that all aspects of a roof system meet all end-user requirements, it does focus on helping customers make sure roof systems adequately resist major perils, such as fire, wind and hail.

So where is FM Global headed? The answer is simple—the same direction it has been for more than 167 years. We continuously are focused on objectively improving construction quality, advancing sound property loss-protection practices and reducing our insureds' loss potentials. Our planned release of RoofNav, a Web-based roof engineering tool, will contribute to that effort by allowing architects, specifiers, contractors and others to easily configure FM Global Research-approved roof assemblies.

The foundation of our business is sound property loss prevention for our policyholders' benefit. The foundation of Baxter's article simply lacks support.

In the future, if you would like to know where FM Global is headed rather than speculating or accepting an outsider's opinion at face value, please call us and ask.

Tom Lawson
FM Global
Johnston, R.I.

Following is Baxter's reply to the letter:

"Judging from the responses to this article from others in the roofing industry and professional associations, it is much less clear to all concerned as to where FM Global is headed than you imply.

"The presentation that precipitated the questions raised in my article came from an FM Global presentation requested by NRCA at the association's 115th Annual Convention and Exhibit in San Antonio. NRCA continually has attempted to assist and work with FM Global Research to help clarify roofing application issues, and I have been involved in the effort for about 15 years. The format that we understand is being incorporated into RoofNav was developed by me and a host of other industry contractors and suppliers for FM Global's use—and at no charge, I may add.

"I am happy you are focused on construction quality and support you in that effort. I have given accolades for your proactive approach to providing information about roof system materials. But in the context that RoofNav was described, I see a lot of confusion coming down the pike. The roofing industry has asked where FM Global is headed, and it still doesn't know."

Following is Professional Roofing's response to the letter:

"Baxter's article clearly was noted as an opinion piece, and Professional Roofing believes it had no obligation to alert FM Global to the article's publication (though Baxter voluntarily sent a copy of the article to FM Global before publication and received no response). Professional Roofing extended an offer to FM Global to author an article refuting or clarifying any points Baxter made. It has declined the offer."