EPDM Lasts – this single ply is hard to beat
Over the last 45 years, Carlisle
EPDM has gained industry wide
acceptance and respect by
providing both immediate and
long term roofing solutions.
During that time, EPDM has also
racked up some impressive
figures in the low sloping market.
As of last year, roofing
contractors had installed over
500,000 warranted EPDM roof
systems, representing over 1858
million square metres. No other
single ply system comes close.
On the new construction side,
more than 92 million square
metres are specified annually in
the U.S. alone.
According to the EPDM Roofing
Association, black EPDM roofs
account for more than 52% of
roofing installations in the
northern U.S., zones with
conditions comparable with
the UK.
Weatherability is the key reason
why more EPDM roofs continue
to perform in the existing
inventory than any other single
ply membrane. In addition to
excellent weathering characteristics,
EPDM is a low
maintenance roofing
system that offers superior wind,
hail and fire resistance.
Ask the experts
Wilbur Kline ranked in the top
100 specifiers by McGraw-Hill is
also a firm believer in the long
term performance of EPDM.
“I can’t remember any kind of
problem with any project in
which I used EPDM membrane”,
says Kline. “I just kept specifying
EPDM because the performance
was consistent.
What makes EPDM such an
outstanding roofing system?
Besides its legendary weatherability,
EPDM is dimensionally
stable, yet expands and contracts
with the building movement in a
variety of climates.
EPDM is virtually immune to
ozone, UV radiation and cold
cracking. The material does not
rely on plasticizers for its
flexibility, so there’s no danger of
the material becoming brittle
from plasticizer loss down the
road.
Seam tapes and accessories
There’s an old adage in the
roofing industry that says a single
ply roof is only as good as its
seams. While early EPDM
systems were almost bullet proof
when it came to weather resistance, the first generation of
products relied on liquid
adhesive for lap seaming.
Though acceptable at the time
industry professionals knew that
a more reliable method would be
needed in order to make the
system a viable, long term
roofing solution.
“From a weatherability
standpoint mil for mil EPDM has
proven to be one of the most
cost effective membranes
available today” says Rene
Dupuis, president of Structural
Research Inc.
Dupuis has probably studied
more EPDM membranes - both
in the laboratory and on the roof
-than any other independent
roofing researcher over the last
30 years. Dupuis is also known
for his objectivity and honesty
when evaluating roofing
systems.
“It’s remarkable in hind sight
that EPDM started out with one
of the more vulnerable lap
systems” he says. “However, the
industry certainly did not rest till
a true high performance tape
system was perfected.”
Walt Rossiter, technical director
for the Roof Consultants Institute
and former research chemist at
the National Bureau of
Standards agrees. “EPDM seam
performance is really a non
issue, it’s simply not discussed
any more”, Rossiter says. “The
steps the industry has taken in
terms of seam tapes and pre
formed accessories has been
fabulous.”
“To be able to take a pre-formed
pipe boot with a taped flange
and slip it over a pipe penetration
is amazing for two reasons” says
Rossiter. “It saves on labour, but
more importantly, it eliminates
stretching and bending of the
membrane, along with the use of
liquid adhesives.”
Rossiter should know, as he
helped author a landmark NIST
study on the performance of tape
bonded EPDM seams in 1997.
“We spent well over three years
analyzing the performance of
taped EPDM seams”, recalls
Rossiter. “One of the things we
discovered was that the strength
of a seam made in a laboratory
and in the field were statistically
comparable. That was not the
case for the old butyl based
liquid adhesives”.