EPDM Roofing Membranes
There are many flat roofing or low
slope roofing solutions. One of the more popular choices in today's market is
the EPDM memberane. EPDM stands for ethelene propylene diene monomer, which is
a rubber product. There are several manufacturers that produce EPDM such as GAF
and Versico. Here are some of the facts and information about Versico EPDM
membranes and systems.
- EPDM is comprised of a polyester reinforcement sandwiched between two layers of rubber.
- It is available in .45, .60 and .75 mil thicknesses.
- Designed for high traffic roof tops such as schools and hospitals.
- Versico's brand comes with QAT Seam Technology which is quick applied tape. This makes installation much faster and more effective.
- QAT quick tape has been known to reduce seaming time by 75%. It also reduces seam failure by providing 30% stronger peel strength and 32% stronger than most other seam tapes on the market.
- The polyester reinforcement in between the layers of EPDM rubber more than doubles the puncture resistant strength compared to non-reinforced membranes.
- Versicos EPDM membranes can be installed as a complete roofing system and qualify for a 20 year NDL "no dollar limit" warranty.
- They can be installed by either mechanically fastening the membrane with screws and plates or by fully adhering (gluing) the membrane with special bonding adhesive. In order to qualify for the NDL system warranty DASH DC bonding adhesive must be used. In order to qualify for a no dollar limit warranty your system must be installed by a Versico approved roofing contractor.
- Fully adhered systems can be warranted against wind resistance up to 120 mph. Mechanically attached systems can carry a 100 mph wind resistance warranty.
For more in depth information please
read the below excerpt from Wikipedia. You can also see Versicos EPDM page on
their website at
http://www.versico.com/index.cfm?act=productdetails&RSC_ID=45.
EPDM rubber
(ethylene propylene diene monomer (M-class) rubber),[1][2][3]
a type of synthetic rubber, is an elastomer
which is characterized by a wide range of applications. The E refers to ethylene,
P to propylene, D to diene and M refers to its classification
in ASTM
standard D-1418. The M class includes rubbers
having a saturated chain of the polymethylene
type. Dienes currently used in the manufacture of EPDM rubbers are
dicyclopentadiene (DCPD), ethylidene norbornene (ENB), and vinyl norbornene
(VNB). EPDM rubber is closely related to ethylene
propylene rubber (ethylene
propylene rubber is a copolymer
of ethylene
and propylene
whereas EPDM rubber
is a terpolymer
of ethylene,
propylene
and a diene-component).
The ethylene content is around 45%
to 75%. The higher the ethylene content the higher the loading possibilities of
the polymer, better mixing and extrusion. Peroxide curing these polymers gives
a higher crosslink density compared with their amorphous
counterpart. The amorphous polymer are also excellent in processing. This is
very much influenced by their molecular structure. The dienes, typically
comprising from 2.5% up to 12% by weight of the composition, serve as crosslinks
when curing with sulphur and resin, with peroxide cures the diene (or third
monomer) functions as a coagent, which provide resistance to unwanted
tackiness, creep or flow during end use.
Properties
EPDM exhibits satisfactory
compatibility with fireproof hydraulic fluids, ketones, hot and cold water, and alkalis, and
unsatisfactory compatibility with most oils, gasoline,
kerosene,
aromatic
and aliphatic
hydrocarbons,
halogenated solvents and concentrated acids.
The main properties of EPDM are its
outstanding heat,
ozone
and weather
resistance. The resistance to polar
substances and steam
are also good. It has excellent electrical insulating properties. It has good
resistance to ketones, ordinary diluted acids and alkalines.
Typical properties of EPDM
vulcanizates are given below. EPDM can be compounded to meet specific
properties to a limit depending first on the EPDM polymers available, then the
processing and curing method(s) employed. EPDMs are available in a range of molecular
weights (indicated in terms of Mooney viscosity ML(1+4) at 125 °C),
varying levels of ethylene, third monomer and oil content.
Mechanical
properties of EPDM
|
|
Property
|
Value
|
Appearance
|
|
Hardness, Shore A
|
40–90
|
Tensile failure stress, ultimate
|
25 MPa
|
Elongation after fracture
in %
|
≥ 300%
|
Density
|
Can be compounded from 0.90 to
>2.00 g/cm3
|
Thermal
properties of EPDM
|
|
Property
|
Value
|
160 µm/m·K
|
|
Maximum service temperature[5]
|
150 °C
|
Minimum service temperature[5]
|
−50 °C
|
−54 °C
|
Uses
An EPDM rubber roof
EPDM rubber is used in seals (for example it is used in cold-room doors since it's an insulator,
as well as in the face seals of industrial respirators in automotive paint
spray environments, where silicone must be avoided). EPDM is also used in glass-run channels, radiators, garden and appliance hose,
tubing, pond liners, washers, belts, electrical insulation, vibrators, O-rings, solar panel heat collectors and speaker cone surrounds. It is also used
as a medium for water resistance in electrical cable-jointing, roofing membranes (since it does not
pollute the run-off rainwater, which is of vital importance for rainwater harvesting), geomembranes, rubber mechanical goods, plastic impact modification, thermoplastic,
vulcanizates, and many other applications.[6][7]
Colored EPDM granules are mixed with polyurethane binders and troweled or
sprayed onto concrete, asphalt, screenings, interlocking brick, wood etc. to
create a non-slip, soft, porous safety surface for wet-deck areas such as pool
decks and as safety surfacing under playground play equipment (designed to help
lessen fall injury).
The most common use however is
probably in vehicles. It is used in door seals, window
seals, trunk seals, and sometimes hood seals. Frequently these seals are the
source of noise due to movement of the door against the car body and the
resulting friction between the EPDM rubber and the mating surface (car painted
sheet metal or glass). This can be alleviated using specialty coatings that are
applied at the time of manufacture of the weather seal. Such coatings can also
greatly increase the chemical resistance of EPDM rubber. Some vehicle
manufacturers also recommend a light application of silicone dielectric grease
to weatherstripping to reduce noise. Other uses in vehicles include cooling
system circuit hoses where water pumps, thermostats, EGR valves, EGR coolers,
heaters, oil coolers, radiators and degas bottles are connected with EPDM
hoses; as well as charge air tubing on turbo charged engines to connect the
cold side of the charge air cooler (intercooler) to the intake manifold.
References
1.
Jump up ^
Ravishankar, P.S. (2012). "Treatise on EPDM".
Rubber Chemistry and Technology 85. p. 327-349.
2.
Jump up ^
Green, Mark M.; Wittcoff, Harold A. (July 2003). Organic Chemistry
Principles and Industrial Practice. Weinheim, Germany: Wiley. p. 170. ISBN 978-3-527-30289-5.
"In addition to natural rubber, many synthetic rubbers…such
as…ethylene-propylene-diene monomer rubber…"
3.
Jump up ^
Louie, Douglas K. (2005). "Elastomers". Handbook of sulphuric acid
manufacturing. Richmond Hill, Canada: DKL Engineering, Inc.
pp. 16–116. ISBN 978-0-9738992-0-7.
"EPDM (Ethylene Propylene Diene Monomer is a M class Rubber containing a
saturated chain of the polyethylene type."