Assembly Instructions
The most important characteristic of
insulation is its ability to retain R-value
and continue to insulate even when
exposed to water for long periods of time.
Over the lifetime of a building or paved
surface, water gets into, and lingers in,
the soil around the construction.
Water is an excellent conductor of heat,
so if insulation is water soaked, R-value is
lost. Also, if absorbed water freezes and
thaws, the insulation structure will break
down over time and structural integrity
can be compromised.
There is extensive messaging from the
EPS industry claiming that EPS performs
the same, if not better, than XPS when it
comes to R-value and moisture. But you
only have to look at the science to see
the real truth – science doesn’t lie.
Science proves XPS is more
moisture-resistant than EPS
*
The EPS industry claims to have “proof”
that EPS is more moisture-resistant than
XPS. This came from one study that was
commissioned by the EPS industry. To
this day, no one has been able to verify or
recreate these same results. In fact, when
asked for the study to be made public,
the full report was not disclosed to
multiple requesters. If the data is truly
valid, then why not show it to the world?
Experts have reviewed numerous
independent technical studies and their
key finds prove that XPS performs better
than EPS in below grade applications.
The use of EPS below grade, is limited
in certain critical applications such as
for insulating frost-protected, shallow
foundations as cited in numerous design
standards published by the American
Society of Civil Engineers (ASCE), the
International Building Code (IBC), and
the International Residential Code (IRC).
XPS is more moisture-resistant
than EPS.
Science proves XPS holds
R-value better than EPS at
lower mean temperatures
when water is present
*
The EPS industry claims that EPS
“holds” R-value better than XPS. The
truth is XPS has a higher R-value than
EPS. The EPS claim compares the
FOAMULAR
®
XPS warranty of 90% to
100% for EPS. However 90% of R-5 is
always more than 100% of R-3.6 to 4.2.
And the FOAMULAR
®
warranty is for
the lifetime of the product.
EPS claims also mention that their
R-value is higher when tested at lower
temperatures. That is true for both EPS
and XPS. What is not mentioned is that
when EPS absorbs water, its R-value
gets lower, even when tested at lower
mean temperature. Meanwhile XPS
continues to have a higher R-value at
lower mean temperatures even when
exposed to water. In real applications,
particularly below grade, insulation
gets wet. Recognition of “real world”
conditions is important when assessing
performance. XPS holds R-value better.
Owens Corning
™
FOAMULAR
®
XPS
Proven Performance
EPS: Open CellXPS: Closed Cell
MANUFACTURING PROCESS MATTERS
SCIENCE DOESN’T LIE
XPS – Extruded Polystyrene
Manufactured in a continuous extrusion process,
that produces a homogeneous, closed-cell,
cross-section.
EPS – Expanded Polystyrene
Manufactured by expanding spherical beads in a mold,
using heat and pressure to fuse the beads together.
While each individual bead is a closed-cell environment,
there are significant open spaces between each bead.
FOAMULAR
®
XPS
BENEFITS EPS
Base products R-5 per inch with High-R
product line at R-5.7 per inch.
R-Value Products range from R-3.1 to R-4.3 per inch.
0.3% maximum water absorption by volume
(ASTM C272) – potential absorption is
very low.
Water Absorption
2-4% water absorption by volume
(ASTM C272) – potential absorption is
10 times greater than FOAMULAR
®
XPS.
XPS maintains product integrity because
of its moisture-resistance. Water does not
penetrate and break down material during
freeze/thaw cycles.
1
Maintaining
Structural
Integrity
EPS is capable of absorbing water, even with
facer on, which will break down material and
cause damage during freeze/thaw cycles.
Passed Exterior Wall Fire Testing.
2
NFPA 285
Fire Tested
Very few EPS manufacturers have completed
testing (UL listed assemblies).
The only XPS to have achieved GREENGUARD
Gold Certification – with strict certification
criteria, including testing, that considers
factors for sensitive individuals and ensures
acceptability for use in schools and healthcare
facilities.
Underwriters
Laboratories (UL)
GREENGUARD
Certication
No EPS manufacturer has this certification.
XPS is reusable and remnants from
manufacturing are recycled back into new
XPS foam insulation. Only FOAMULAR
®
XPS
is third party certified for recycled content
(SCS Certification) with 20% minimum.
Recycle/Reuse
EPS is recyclable and reusable. Recycled
content is not certified from a third party.
Most are listed with 15% recycled content.
Industry’s only LIFETIME LIMITED WARRANTY.
3
We stand behind our product for the life of
the home or building.
Warranty Warranties range from 0-20 years.
World-class, industry-leading building science
capabilities for 75 years. Customers can talk
directly to a building science leader with
GET-TECH email and support resources.
Technical Support Technical support offered by manufacturers.
XPS can contribute to meeting LEED
®
credit
criteria. Additionally, FOAMULAR
®
XPS is
available as an Environmental Product
Declaration (EPD) – an additional area where
contributions to LEED
®
points can be made.
LEED
®
Credits Qualifies for LEED
®
credits.
1
ASTM C666.
2
Approved under variety of masonry veneer finishes, over steel stud frame or masonry back-up walls.
3
See actual warranty for complete details, limitations and requirements.
FOAMULAR
®
XPS vs. EPS:
A Head-to-Head Comparison
Cell wall
Cells in each bead
Open space between
beads that allow the
intrusion of water
Closed cell
*ASTM C272 and ASTM C518. Also see Owens Corning technical document: “Extrusion Matters” for more details.