| 1.
|
What
is EPDM?
EPDM is an elastomeric compound that is manufactured
from ethylene, propylene, and a small amount of diene
monomer. These ingredients are synthesized to produce
a product that exhibits a high degree of ozone, ultraviolet,
weathering and abrasion resistance, and outstanding
low temperature flexibility. These ingredients also
contribute to resistance to acids, alkalis, and oxygenated
solvents (i.e., ketones, esters, and alcohols).
|
| 2.
|
What
does EPDM look like?
Black EPDM has a smooth surface similar to natural gray
slate and does not contain surface granules that can
eventually be lost on other materials. |
| 3.
|
How
can the performance of EPDM be gauged over the last
40 years?
With over 1 billion square feet of membrane installed
worldwide, EPDM has established itself as the membrane
for all climatic conditions. This is supported by various
laboratory studies and actual field installations. This
excellent track record is the result of unique and unmatched
physical characteristics:
- EPDM
has superior resistance to UV (ultraviolet) radiation
- EPDM
has unmatched resistance to thermal shock
- EPDM
exhibits superior resistance to cyclic fatigue
- EPDM
has superior resistance to hail damage
- EPDM
will not become brittle and will not shatter due
to low temperature flexibility
|
| 4.
|
How
does the performance of EPDM membrane compare to built-up
roofing?
Expansion and contraction, ponding, moisture, thermal
shock, and temperature extremes are all factors that
promote premature degradation of a roofing membrane.
The great elongation and low temperature flexibility
of EPDM membrane accommodate building movement in various
climatic conditions without stressing the material.
Its moisture absorption resistance allows the material
to be installed in assemblies with lesser slope than
other single-plies and makes it tolerable to incidental
ponding and deflection. Unlike built-up roofing, EPDM
membrane does not contain organic material that can
decay as the result of moisture caused by condensation
or leaks. EPDM membrane, due to its ability to withstand
extreme temperature, can be successfully used in assemblies
with greater thermal resistance (thicker insulations
with higher R-values). The ability of a roofing membrane
to withstand temperature extremes is an important trait
of a high performance material because temperature extremes
could promote premature membrane aging and reduce the
life expectancy of a roof. |
| 5.
|
What
is the maximum size sheet for EPDM membrane?
Sheets as large as 50 feet in width are produced mostly
for use in ballasted and mechanically fastened applications.
Narrower widths are also produced to offer applicators
greater flexibility in positioning membrane.
Narrower sheets are also produced without factory seams
(seamless) for use primarily in adhered and mechanically
fastened applications. The major advantage of seamless
material is the elimination of factory splice T-joints
that occur when factory seams intersect with field splices.
This reduction in T-joints significantly increases the
potential for watertight performance by eliminating
potential "water channels" into field splices.
Both narrow and wide sheets are manufactured in varying
lengths from 50' to 200'. |
| 6.
|
What
is the difference between black EPDM and white EPDM
membrane?
In addition to the oils and the polymers used to make
an EPDM membrane, another ingredient is added to the
mix to enhance UV resistance. In the case of a black
membrane, carbon black is added, which converts UV rays
into heat. With white membrane, in lieu of carbon black,
titanium dioxide is typically used to reflect UV rays
and prevent it from attacking the polymer. |
| 7.
|
Can
EPDM membrane be used in roof top garden applications?
EPDM has a proven track record in various waterproofing
and pond lining applications which somewhat resemble
roof top applications. However, there are certain rules
that should be followed when designing a roof top garden
regardless of the type of membrane used:
- Select
a membrane with high puncture resistance
- Establish
redundancy in the waterproofing assembly by overlaying
splices
- Design
the assembly to provide slope and proper drainage
at the membrane level
- Incorporate
protection above the membrane to aid against root
growth and possible puncture
- Incorporate
a drainage layer and a root barrier to influence
root growth away from membrane
- Select
proper growth media for the type of roof garden
intended
|
| 8.
|
Does
EPDM require systematic maintenance or additional coatings
or treatment to achieve its life expectancy?
No. No special coating or other surface treatment is
required. General maintenance in the form of good housekeeping
should periodically be performed to remove debris and
leaves, and to investigate the performance of other
components. |
| 9.
|
Are
temperature limitations associated with the installation
of EPDM roofing system?
In accordance with ASTM standard D 746, EPDM membrane
has a brittleness temperature of -49 F. While the membrane
will remain flexible and pliable in extremely cold temperatures,
adhesives, flashings and tapes should be kept at room
temperature (hot boxes are usually used on the rooftop
to rotate adhesive cans and rolls of flashing). Although
roofing contractors may select not to work in sub-freezing
temperatures due to safety concerns, many EPDM installations
have taken place in temps below 20 F. |
| 10.
|
Is
the performance of the EPDM membrane adversely affected
geographically due to temperature extremes?
In laboratory testing EPDM is subject to the most severe
heat aging where samples are subjected to temperatures
of 240 F for 4 weeks. Also, in several studies field
samples were collected from various geographic locations
after years of exposure and in both cases (laboratory
and field), the physical properties of the samples exceeded
the original ASTM specification. Presently, there are
numerous EPDM installations throughout colder regions
in the U.S. (i.e., Alaska, Minnesota) as well as in
the hot and humid climates of southern Florida and Texas.
For the past 25 years, EPDM has been the roofing membrane
of choice for many commercial and manufacturing facilities
internationally. The material will not shatter in extreme,
cold temperatures and remains flexible under severe
thermal shock such as in dessert areas where evenings
are extremely cold and days extremely hot. |
| 11.
|
Is
EPDM environmentally beneficial?
EPDM is one of the most sustainable and environmental
materials used today in the construction industry. Its
excellent performance transfers to low life cycle costs
and less impact on the environment.
The initial production of the membrane has a low embodied
energy number (the amount of energy required to produce
and implement a product from material extraction, manufacture,
and installation). In addition several other components
(such as cleaners, primers and adhesives) were developed
for use with the EPDM membrane to reduce VOC (Volatile
Organic Compounds) emissions during installation.
Post-industrial products can be reincorporated (recycled)
into the manufacturing of other roofing products and
accessories (i.e., walkways and roofing tiles), thus
minimizing the impact on landfills. |
| 12.
|
What
is the expected longevity of EPDM membrane?
With many EPDM installations exceeding 40 years of exposure
in the field under various climatic conditions, none
of the material tested has shown alarming signs of degradation.
Even though it would be difficult to predict, studies
have shown aged EPDM membrane as having a potential
life expectancy of 50 years. |
| 13.
|
Can
EPDM be coated or painted?
Acrylic coatings are available that can be applied directly
to a prepared EPDM surface. Preparation usually consists
of cleaning the EPDM with a pressure washer and a detergent
solution or wash. Latex-based paint products can also
be used, however, the EPDM manufacturer should be contacted
prior to application to ensure compatibility and continuation
of warranty coverage. |
| 14.
|
Can
EPDM be used in installations other than roofing?
Yes. EPDM has been used in various installations such
as pond liners, tunnels, foundations, thru-wall flashings,
terraces, garden roofs, and RV roofs. |
| 15.
|
Generally
speaking, is an EPDM single-ply membrane roofing system
cost effective?
Dollar-for-dollar, EPDM roofing systems are the greatest
value in the low slope commercial roofing industry.
While installation costs vary from system to system
as well as from building to building, generally, ballasted
roofing systems have the lowest installed cost per square
foot followed by mechanically fastened and fully adhered
systems. |
| 16.
|
How
long can an EPDM roofing system be warranted?
Generally speaking, system warranties that cover material
and labor costs are available; and different manufacturers
offer various assemblies with standard warranties that
vary from 5 and 10 to 15 and 20 years. In addition,
premium coverage up to 30 years is available and can
include coverage for higher wind speeds, incidental
puncture, and hail resistance. |
| 17.
|
How
popular is EPDM single-ply membrane?
Within the United States, EPDM accounts for over 1 billion
square feet of new roofing annually and represents approximately
35% of the entire roofing market. In Europe the market
share is around 12% and growing. While it is difficult
to predict percentages in other markets, accelerated
growth is reported in the Middle East and China as well.
|
| 18.
|
Would
repairs to an EPDM membrane be impaired by aging?
No. One of the most unique attributes of EPDM is its
ability to be easily repaired as well as its potential
for restoration unparalleled in the roofing industry.
The characteristics of the membrane are such that, even
after years of field service and exposure to the elements,
repairs and/or modifications, such as the installation
of a new rooftop unit, can be accomplished with ease
and with the expectation of long-term performance.
Unlike other roofing systems that degrade or become
brittle over time due to UV exposure, EPDM single-ply
membrane maintains its integrity and flexibility. This
allows for modifications as easy as washing the membrane,
preparing the roofing membrane surface, adhesive applications,
and the installation of new material. |
Why EPDM?
FAQs
ERA Research & Resources
Press Room
Who We Are
Continuing Education
Links
Contact Us
