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Have Asphalt Shingles Improved? - Continued

Tests vs. Reality

In fact, companies still argue over whether the tests in the existing standard relate to the actual causes of performance failures.

In the early 1990s, the Asphalt Roofing Manufacturers Association (ARMA) argued that ASTM D 3462, especially the tear-test part, didn't bear on the cracking and splitting problem. Asserting that other shingle qualities such as pliability and tensile elongation were more the issue, ARMA argued against raising or enforcing the tear-test requirement. Roofer organizations like the National Roofing Contractors Association (NRCA), the Midwest Roofing Contractors Association (MRCA), and the Western States Roofing Contractors Association (WSRCA) took the opposite side. "NRCA's opinion is that compliance with D 3462 is the principal indicator," says Tom Bollnow of the NRCA technical services staff. "It's not the only causal effect, but it is an indicator that the shingle is more likely to perform than one that doesn't comply." On the other hand, notes Bollnow, "You have to be careful. There are certain things a manufacturer can do to a shingle to increase the tear strength that might have adverse effects on the rest of the shingle. And there are some shingles that don't meet the ASTM 1700-gram tear-strength minimum that are performing fine." "But in eight years," Bollnow says, "they haven't been able to come up with another test. This is the one we have." Engineer Kent Blanchard is a TAMKO executive who serves on the ASTM task force for the D 3462 standard. He questions relying on the standard as a guide: "D 3462 has become a proxy for quality, and that is not right. If you really want to know how the shingle is made, you've got to know about the filler, the asphalt, the granules.... [A shingle] could meet D 3462 and still have a problem with the asphalt or the filler. Even 2000 grams of tear strength does not guarantee that you are not going to have problems with the shingle." Blanchard argues in favor of market forces. "The people that have to determine whether the product is good enough are the ones who install it. They buy a shingle and if they don't have problems with it, they will stick with that shingle. When they start having problems they bail out of the shingle. I know of roofing manufacturers who knew they were putting out a bad shingle, but if you are in it for the long haul, you can't do it that way." "There is a lot more to the buying process than an ASTM standard," insists Blanchard. "That's not to say, 'let's don't have any standard,' but don't put your trust in a standard. You have to put your trust in the company, that they know how to make a good shingle." Mike Noone counters Blanchard this way: "Whatever he may say, his company's shingles still pass D 3462." CertainTeed, like most manufacturers, routinely runs its competitors' brands through ASTM testing, and Noone says, "I don't think I've ever seen one of theirs [TAMKO's] that doesn't pass D 3462. Most of them are well above it." And in fact, a check of TAMKO's web site shows that their product literature for one brand, the Stormfighter, claims test results of more than double the ASTM minimums.

ASTM and the Building Code

A decade ago, with the cracking problem hurting their businesses, roofers started pushing to include the D 3462 shingle standard in building codes. In 1997, the roofers got their way. The most recent versions of ICBO, BOCA, and SBCCI codes require D 3462 compliance, as does the new International Residential Code created jointly by all three bodies. Only in states or municipalities where pre-1997 versions of the codes still apply are non-ASTM-compliant shingles allowed. Tim Ryan, a building official in Overland Park, Kan., is on the International Code Council board of directors. Overland Park has adopted the new International Code, and Ryan says his office is enforcing ASTM D 3462 for asphalt shingle roofs. "Different localities handle it differently," says Ryan. "Some require separate permits for roofing, some incorporate it into the general building permit. Some want to be out at the site when they deliver the roofing material, because the product's not labeled — just the wrapper is. Our guys will pick up the wrappers off the ground to see if the shingles are properly labeled. If we found a non-compliant shingle on the roof, we'd make them take it off, or else get an evaluation report from the manufacturer that says it does comply."

Verifying Compliance

ASTM doesn't perform any testing itself, relying on manufacturers to monitor their own compliance with standards. In 1997, Consumer Reports magazine ran a selection of shingle brands through the ASTM tear test and printed their findings. They discovered that some shingles whose bundle wrappers claimed compliance with ASTM D 3462 actually failed the tear-test minimum. (Not surprisingly, shingles that weren't labeled as ASTM-compliant flunked also). With shingle buyers questioning the manufacturers' self-certification, companies began turning to independent certifiers. Underwriters Laboratories (UL) has long had an independent testing program to certify that fiberglass-asphalt shingles meet the ASTM test for Class A fire resistance. Now companies can enroll in a similar UL program that certifies compliance with ASTM Standard D 3462. A shingle that tests out okay, and continues to pass tests monitored by UL in random factory visits, gets the right to use the familiar "UL" mark on its bundles. CertainTeed was the first to get the UL stamp; after buying out shingle makers Bird, Celotex, and GS, CertainTeed brought those brands into compliance and now has them UL-certified also. Other companies have since followed suit, and the majority of brands now have UL certification. However, many companies still make ASTM-compliant and substandard versions of the same brand, selling one where compliance is enforced and another where it isn't. Also, it's important when you check for the UL sign to make sure that it relates specifically to ASTM D 3462 and not some other standard: All fiberglass shingles have been marked as meeting the UL Class A fire resistance standard for many years, but that has no bearing on the strength or durability of the shingle

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ASTM Standard D 3462 for fiberglass asphalt shingles includes a nail pull-through test using a special apparatus (left) and a tear test using the Elmendorf tear-test machine (right). Experts say that shingles meeting the test minimums at the time of manufacture don't experience splitting and cracking on roofs. Many companies now have their testing results verified by Underwriters Laboratories.

Aging concerns. There is some concern about whether shingles that pass the standard when they are manufactured will keep their good qualities over time. Tear-test values, in particular, have been reported to drop quickly: UL's Ken Rhodes reports that some shingle brands that pass factory testing may flunk after a few months of storage in the package. Rhodes says nail-withdrawal and pliability results don't show the same decline. CertainTeed's Mike Noone says that this drop in test values has only been seen in a few cases, but he says it has prompted some manufacturers to argue that the D 3462 standard should only apply on the day the shingles are made, not months later. Noone disagrees: "You should be able to test the shingles three or six months later and find that they pass." In the field after years of service, it is clear that test results drop. Carl Cash, an engineer with consulting firm Simpson, Gumpertz, and Heger, has investigated large numbers of failed roofs, and says shingle samples from roofs with splitting and cracking show very low tear test values — 400, 800, or 1000 grams on the tear-test, rather than the standard minimum of 1700 grams. These low values after years of exposure aren't in themselves considered a violation of ASTM D 3462, which is primarily a manufacturing standard; but they may be a good argument in favor of choosing shingles that far exceed the minimums, rather than barely passing them. Even so, Cash admits, "There are shingles out there that have a lower tear strength than 1700 grams that are performing adequately."

Installation Smoke Screen

Companies that make shingles, or any other product, typically make it a practice to look at installation when the product's performance is called into question. In the case of the well-known cracking problem, says Carl Cash, that is a smoke screen. Cash chairs ASTM's overall roofing committee, with responsibility for commercial "flat" roofing products as well as steep-slope materials. He has served as an expert witness for the plaintiffs in lawsuits over defective shingles. Cash states flatly, "There is nothing a roofing contractor can do to cause a roofing shingle to split, and there is nothing a contractor can do to prevent a shingle from splitting if it wants to." "One of the things manufacturers focus on is the lack of ventilation in the attic," notes Cash. "That is a load of [baloney]. I have seen vented and unvented roofs side by side with the same orientation, same contractor, both split to the same degree. Ventilation is important for survival of the roof deck, but not for preventing shingle splitting."

About Warranties

Most experts agree that with shingles, you get what you pay for — usually. The cheaper shingles are more likely to suffer early deterioration, while the higher-priced shingles will probably last longer. Most often, a company also offers longer warranties on the pricier shingles. And although "20-year" shingles have become scarcer, some companies still produce a "20-year" shingle at bargain prices as well as a middle-of-the-market "25-year" line, and perhaps a premium line of shingle with a warranty term of 30 or 40 years, or even a "lifetime" warranty. Technical people throughout the industry, however, generally agree that the warranties are little more than a marketing device, and can't be considered an accurate predictor of shingle life. Read the fine print. As for the protection warranties offer the buyer, other factors are more important than the length of the term. Most warranties are prorated, losing a portion of their value every year; but some have an introductory term of five, seven, or ten years in which the full value is covered. Most warranties only cover the original buyer, but some will cover a second or third homeowner, at least in part. And the restrictions on installation details also vary slightly, although virtually all warranties can be voided if the installer doesn't follow the instructions on the label. The big difference in warranties relates to this last point — whether the company will honor it or use some installation issue to avoid paying. Very few roofs, if any, are perfectly installed, and if a company is determined to avoid paying out, they can usually come up with an excuse to do so. So it really comes down to whether the manufacturer is motivated to stand behind its product, and has the means to do so. In this regard, TAMKO's Kent Blanchard's point may hold: It's the installer who ultimately has to judge the manufacturer's trustworthiness. "I was 30 years in the contracting industry," says the NRCA's Tom Bollnow. "As a contractor you try to associate with one or two manufacturers that are going to provide service. Out of thirteen manufacturers, there might be one or two that have a problem, but seven or eight are going to be pretty much the same." On the other hand, notes Bollnow, "Companies can change hands, policies can change. That's the value of belonging to a contractor association — you get to talk to other contractors, and if you hear of problems with a company that you have been dealing with, you watch out."


Ted Cushmanis a contributing editor for The Journal of Light Construction.