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EPS Solutions for
Continuous Insulation
Residential housing design continues to move towards the
development of high performance sustainable building systems.
To be sustainable, a building must not only be efficient and
durable but also economically viable. According to the U.S.
Department of Energy (DOE), Heating and cooling accounts for
50% to 70%of the energy used in an average home. DOE states
that homeowners may be able to reduce their energy bills from
10% to 50% by increasing the amount of thermal insulation.
Insulation saves money, increases home comfort and protects
the environment by reducing energy use. Insulated EPS foam
sheathing is an effective and cost-efficient way to increase the
R-value of exterior walls and meet prescriptive requirements for
continuous insulation (CI).
CI is a proven solution for long term energy savings and is
the most effective way to insulate the building envelope.
The Building Energy Codes define continuous insulation as
"insulation that runs continuously over structural members and
is free of significant thermal bridging". Thermal bridging occurs
when there is a break in the continuity of the insulation layer,
which results in heat loss.
Thermal bridging through framing components reduces
envelope insulation performance by 15-20% in wood frame
construction and by 40%-60% in metal frame construction.
This means that a typical 6" metal stud wall construction with
R-19 fiberglass batt insulation actually performs at a dismal R-9.
When CI is properly installed the approximate full R-value of the
insulation material is achieved.
For some regions continuous insulation (CI) has been an energy
code requirement since the release of ASHRAE 90.1, however,
revisions to the 2012 International Energy Conservation Code
(IECC) have created opportunities for CI systems. With a
heavy emphasis on building insulation and building envelope
construction, these revisions require a 30 percent increase in
energy savings in residential and commercial buildings (as
compared to the 2006 code) and specifically apply to the
construction of residential and commercial walls. The updated
IECC also calls for increased levels of insulation, particularly for
residential walls.
Insulated EPS foam sheathing allows CI systems to achieve
the new IECC R-value requirements. EPS used on the exterior
surface of the studs minimizes the temperature differential
between the cavity and studs and prevents the transfer of heat
or cold.
When exterior rigid EPS foam insulation is integrated into the
enclosure assembly it acts not only as insulation but also as the
primary sheathing and, in certain areas, as the drainage plane
and vapor control layer for the wall assembly. It protects against
condensation on the inside wall by keeping the interior of the
wall warmer and above dew point temperature. This system
combined with advanced framing concepts can provide cost
savings from the reduction of building materials used (fewer
studs, the elimination of plywood or OSB sheathing and house
wraps), and the reduction of construction waste (incorporating
standard construction product dimensions in the design of the
building to minimize cutting).
Insulated foam sheathing has these additional advantages:
• Reduces thermal bridging through wood studs, saving
energy and improving comfort.
• Easier, safer and faster to cut and install than heavier-weight
sheathing products.
• Usually more cost effective than plywood or oriented strand
board (OSB).
Insulated EPS foam sheathing can be specified as a replacement
for non-insulating sheathing such as OSB and can be used in
both new and retrofit construction. It's one of the only ways to
radically improve the R-value of older homes while retaining the
house's character. Even small energy efficiency improvements
on a large scale can have a big impact on resources and the
environment.
EPS has been used in a wide array of groundbreaking new
construction applications, solidifying its reputation as a versatile,
high performance material. Time-tested and trusted to provide
a stable, superior insulation envelope for the life of the building
it's an exceptional choice for a continuous insulation system. n
ASTM C578, Standard and Specifications for Rigid,
Cellular Polystyrene Thermal Insulation, is the material
standard that covers the types, physical properties and
dimensions of cellular polystyrene intended for use as
thermal insulation in the United States. CAN/ULC-S701-01,
Standard for Thermal Insulation, Polystyrene Boards and
Pipe Covering is the National Standard of Canada that
specifies requirements for EPS insulation material.
EPS-IA is a member of the Foam Sheathing Committee
which provides information on foam sheathing
construction details.
