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
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
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
"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
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
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."
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
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
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
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."
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
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
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
"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
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.