Letters

The Polyisocyanurate Insulation Manufacturers Association (PIMA) would like to respond to polyisocyanurate roof insulation issues raised by Dick Baxter, president of CRS Inc., Monroe N.C., in "A different look at polyiso," June issue, page 40.

PIMA understands Baxter's opinions are his and do not reflect the views of Professional Roofing or NRCA. However, PIMA believes the article lends credence to a poor technical investigation and continues a pattern by Baxter of attacking the polyisocyanurate insulation industry using inappropriate test methods and conditions. In one clear case, Baxter cites "problems" with a polyisocyanurate board he admits was stored improperly outside in shipping wrappers. His comments about job-site experiences are the result of improper storage, installation and material handling.

By paging through the article and reading the text below the pictures, one would get the impression polyisocyanurate roof insulation readily absorbs water and contractors can expect to find these problems at job sites. Only by digging through the article can one discover Baxter placed the depicted foam samples—with and without facers—"in an autoclave for 60 minutes." Not only is autoclave facer testing unique to Baxter, but left unsaid in the article are the conditions one can find in an autoclave.

For the uninitiated, an autoclave is used to sterilize materials by exposing them to saturated steam under pressure of about 15 pounds per square inch (103 kPa) at a temperature of about 220 F to 250 F (104 C to 121 C). Obviously, destroying a sample by an autoclave is not real-world conditions. PIMA is accustomed to criticism from Baxter that ASTM International standards don't reflect the real world. We feel the same about his autoclave test.

We are surprised Baxter was unaware of the history of facers for polyisocyanurate roof insulation. Fiberglass-reinforced cellulosic facers successfully have been used on polyisocyanurate boards since 1984, and since 1990, they have been the predominate facer in the industry. For nearly 20 years, polyisocyanurate products with these facers have served the industry well.

Glass fibers used in these facers contribute to dimensional stability because cellulose itself will absorb moisture and expand when wet. Facer manufacturers typically use long and short fibers and may include recycled scrap glass. The loading of glass fibers far exceeds Baxter's claim of "only three fibers" that he found in a small sample. The polyisocyanurate foam also contributes to the products' dimensional stability. Polyisocyanurate also has been produced with fiberglass facers for several years, which can be ordered from polyisocyanurate producers. Baxter's assertion that facers changed with the reformulation to pentane blowing agents is totally inaccurate.

As to facers' flammability, Baxter should know all foam insulation products (as well as several other classes of roofing products, such as fiberboard, perlite, membranes and asphalt) are combustible. Polyisocyanurate manufacturers warn about combustibility on their products' packages. Readers also should be aware polyisocyanurate roof insulation with facers in place are subjected to and pass all required fire tests to meet Underwriters Laboratories Inc., FM Global and building code requirements.

Baxter ends the article with a long list of items that, on balance, are fair but overstated. PIMA can boil them down to a much more succinct list, which follows:

• Contractors should call manufacturers with any questions about specifying, purchasing, storing and installing polyisocyanurate insulation.
  
  
• Proper storage of polyisocyanurate insulation at the job site [is necessary] for keeping the product dry. Contractors should use weather-protective tarpaulins or covers.
  
  
• If there is a problem with polyisocyanurate insulation at a job site, contractors immediately should call the manufacturer.
  
  
• Contractors should install polyisocyanurate insulation according to manufacturers' instructions. If the instructions say "do not torch" facers, contractors shouldn't torch the facers.
  
  

PIMA members consistently produce quality products that perform as intended when stored, handled and installed according to manufacturers' instructions. To quote CRS' Web site: "The contractor is the last link in the quality-control process for the roofing system. The best quality material improperly or ineffectively installed will not perform to expectations."

Jared Blum
PIMA
Alexandria, Va.

Following is Baxter's response to the letter:

"I am surprised it took this long for a reaction from PIMA. Oddly enough, most PIMA members were provided with the article and photographs long before publication; the only comment I received is that the paper facers could be a problem. All the polled manufacturers either had fiberglass facers available or were attempting to develop acceptable fiberglass facers for roof insulation products.

"I didn't 'admit' anything about improper storage; the comment and observation were made to call attention to the fact that the paper facers may adversely react to improper storage and field conditions correlated to laboratory exposure. And one doesn't have to ‘dig' far to determine how the comparative testing was conducted. The use of an autoclave in comparative testing only accelerates potential variable conditions among products.

"There was no ‘assertion' that the change in facers was coincident to or necessitated by changes in blowing agents. Facers on polyurethane and polyisocyanurate foam roof insulation products have been changed innumerable times since Apache Products Co., Anderson, S.C., first introduced polyurethane foam roof insulation (and yes, I do remember the history of cellular plastic foam roof insulation from its inception). But the use of virtually 99 percent recycled organic fiber facers appears to have been motivated solely for competitive pricing, not performance. The fact is that recycled paper facers are OK for mechanically attached roof insulation applications. They are not necessarily suitable or desirable for adhered insulation applications because of the extreme dimensional instability caused directly by the drying of the paper facers exposed on top surfaces.

"Thanks to PIMA for abbreviating my list of precautions, but I think its list should be considered ‘supplemental' to the ‘long list' I suggested.

"I believe contractors are the last link in the quality-control process. But only recently have PIMA members provided contractors with a choice of products (a choice of compressive-strength properties in some instances and a choice of facers in others). I like to think my observations and the work completed by NRCA contribute to some changes to make things better."