Expanded polystyrene (EPS) has been used as an insulation material for over 60 years. It is produced by expanding polystyrene beads with steam, which causes them to expand up to 50 times their original size. EPS has beneficial properties for insulation such as high R-values, moisture resistance, and versatility. Plasti-Fab is a leading manufacturer of EPS insulation products in North America, with expertise in EPS applications for buildings and other construction projects.

1. Expanded Polystyrene - EPS: Molecules to Insulation Products & Solutions
Lawrence Le Roux - Plasti-Fab - Sales Manager ON & QC
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1. EPS - A Brief History: (For detailed info: https://en.wikipedia.org/wiki/Polystyrene )
German, Eduard Simon accidentally discovers styrol in 1839. About 80 years later it was
discovered that heating styrol starts a chain reaction, which produces macromolecules. This
eventually led to the substance receiving its present name, Polystyrene. EPS raw materials,
Styrene Monomer have remained consistent for +60 years.
2. Manufacturing Process for EPS:
Pre-Expansion: Upon contact with steam the pre-foaming agent pentane starts to boil and the
beads are expanded to between 40 to 50 times their original volumes.
Pre-maturing: After expansion the EPS beads undergo a maturing period in order to reach an
equilibrium temperature and pressure.
Block Moulding or Shape Moulding: EPS beads are pumped into a mould and reheated with
steam. Pre-foamed beads expand further, completely fill the mould cavity and fuse together.
The beads are moulded to form blocks or customised products. When moulded, volume of EPS
= 2% Product + 98% Air.
3. EPS Physical Properties, Benefits, Testing, Facts etc. (White EPS Insulation Products):
Versatile EPS possesses physical and mechanical properties ideal for most insulation
applications and specifications. Closed cell structure provides good strength to weight ratio.
Density: Varying Densities from 0.70 pcf to 3.0 pcf.
R-value: EPS insulation delivers constant ‘’true’’ R-value. Pentane is used to blow polystyrene
into its final lightweight expanded cellular form. During the process, pentane is replaced by air
in the small air pockets within EPS polymer matrix. The National Institute of Standards &
Technology (NIST) uses EPS as the standard test reference material for thermal

2. Expanded Polystyrene - EPS: Molecules to Insulation Products & Solutions
Lawrence Le Roux - Plasti-Fab - Sales Manager ON & QC
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conductivity: Standard Reference Material for Thermal Conductivity (SRM 1453). Refer to
Can/ULC - S701 and ASTM C578 tables below for additional R-value information.
Does Moisture affect the Thermal Performance of EPS Insulation? Yes, minimal impact as
proven over 30 years of testing in both residential and commercial construction. Energy
Division of the Minnesota Department of Public Service found that found that seven-year-old
samples of EPS used in exterior foundation insulation showed moisture levels of only 0.13%. It
also concluded that the EPS insulation retained between 95 and 97 percent of its thermal
efficiency and that there was no effect on its thermal efficiency and that there was no effect
on its compressive or flexural strength properties.
Compressive Resistance: Varying compressive resistance options from 2.2 psi to 60 psi.
Dimensional Availability: Not many insulation types offer the dimensional availability thickness
of EPS? Moulded EPS can be offered at a thickness of up to 38’’ thick in 2’ x 8’ and 4’ x 8’
options. It provides a great option for increased R-value and void applications in commercial
and residential construction.
Green Building & Energy Efficiency: EPS is an ideal choice for green building designs, offering
tangible environmental advantages with energy efficiency, recycled content, mold resistance
and indoor environmental quality. EPS can help meet other green building goals via localized
manufacturing, which reduces the impacts of transportation and through its use in innovative
applications that improve the overall environmental performance of the building envelope.
EPS Fire Performance & Safety: Flame retardants used in foam plastic insulation allow them to
meet building code fire performance requirements when used as a component in building
assemblies. EPS insulation products contain Brominated copolymer flame retardant of less than
1 % by weight. It is recommended that expanded polystyrene should be protected by a thermal
barrier in specific applications as referenced in the International Code Council (ICC)
and Canadian Materials Construction Centre (CMCC) building codes.
Sound Transmission: As a single component, lower density EPS is poor sound barrier? Then
again, EPS or any other insulation will never be used as a single component building product in
a wall assembly? Expanded polystyrene, when used in combination with other building
materials effectively reduces the transmission of airborne sound through partitioned walls,
ceilings and floors.
Water / Moisture Resistance: EPS is non-hygroscopic and does not readily absorb moisture
from the atmosphere. Its closed-cell structure reduces the absorption and/or migration of
moisture into the insulation material. Although EPS provides a high level of moisture resistance
and breathability, recommended design practices for walls and foundations should be followed
in the selection of vapor and moisture barriers for severe exposures. Simply put, you don’t build
in a lake or swamp?

3. Expanded Polystyrene - EPS: Molecules to Insulation Products & Solutions
Lawrence Le Roux - Plasti-Fab - Sales Manager ON & QC
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Drying Potential of Polystyrene Insulations under Extreme Environmental Cycling Conditions:
The EPS Industry Alliance commissioned Intertek Testing Services NA Ltd., an independent test
Laboratory, to conduct tests on several types of polystyrene foam using ASTM C1512, Standard
Test Method for Characterizing the Effect of Exposure to Environmental Cycling on Thermal
Performance of Insulation Products; a rigorous environmental cycling laboratory test method.
Full test report: https://www.epsindustry.org/sites/default/files/Below_Grade_104_33116.pdf
Testing - Canada:
EPS Insulation is manufactured to meet or exceed the requirements of CAN/ULC-S701, Standard
for Thermal Insulation, Polystyrene, Boards and Pipe Covering. For additional testing info:
https://tinyurl.com/ycwgxljs
Testing - US:
EPS Insulation is manufactured to meet or exceed the requirements of ASTM C578, Standard
Specification for Rigid Cellular, Polystyrene Thermal Insulation, and applicable building codes.
For additional testing info: https://tinyurl.com/y72snws8
Geofoam Testing - Canada & US:
This specification covers the types, physical properties and dimensions of rigid cellular
polystyrene intended for use as geofoam. For additional testing info:
https://www.plastifab.com/products/geofoam-sol/geospec.html
4. EPS Insulation Game Changer - BASF Neopor® GPS (Graphite Polystyrene) Rigid
Insulation:
What BASF Neopor® GPS (Graphite Polystyrene): Neopor is patented and manufactured by
BASF chemical company. BASF integrates high-purity graphite particles into polystyrene beads
to create the raw material Neopor.

4. Expanded Polystyrene - EPS: Molecules to Insulation Products & Solutions
Lawrence Le Roux - Plasti-Fab - Sales Manager ON & QC
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How Does Neopor Insulation Work: Neopor works in the very same way as traditional white
EPS insulation, with one primary difference - the high-purity graphite particles give the
insulation a reflective property which increases the energy efficiency of the material.
Illustration of How Neopor Insulation Works (Cont.):
Traditional White EPS Insulation BASF Neopor® GPS (Graphite Polystyrene)
Testing:
R-value is not affected by density with BASF Neopor® GPS (Graphite Polystyrene). As viewed in
the table above, R-value of R4.7 per 1’’ and R5.0 per 1-1/16’’ for Type 1, 2, & 3 made with
Neopor
5. EPS Product Applications:
Insulating: Roofs, Exterior Sheathing, Basement Walls - Interior + Exterior,
Basement Floors - Above + Below Concrete Slab, Hydronic Flooring, ICF, SIP
Walls + Roofs and Radon Mitigation
EIFS, Roofing, Cavity Walls, Precast Concrete Panels, SIP Walls + Roofs, ICF,
Pipe & Vessel Insulation, Cold Storage, Ice Rinks, Utility Insulation, Split
Slabs, and Radon Mitigation

5. Expanded Polystyrene - EPS: Molecules to Insulation Products & Solutions
Lawrence Le Roux - Plasti-Fab - Sales Manager ON & QC
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Insulating: Cathedral Ceiling, Exterior Sheathing, Interior Basement Walls +
Floor, ICF for Additions, SIP Additions
Road Embankment Construction, Floor Slab Design, Landscape
Applications, Compressible Fill Applications, Utility Line Insulation, Load
Reduction on Buried Utilities, Retaining Walls Applications and Slope
Stabilization.
6. Plasti-Fab - EPS Product Expertise since 1968:
Through EPS product research and development, Plasti-Fab is recognized as leading experts in
the EPS industry. Plasti-Fab continues to deliver EPS product innovation and solutions by
understanding our customers' needs. We back our product performance with ongoing research
and testing. We pride ourselves on maintaining a consistent link between product performance
knowledge and product application knowledge.
Over the past 53 years, Plasti-Fab has published series of EPS Technical Documents, PIB’s –
Product Information Bulletins and How to Videos. These EPS technical and knowledge resources
can be accessed by following the Links Below:
https://www.plastifab.com/technical-library/tcs-plastifab.html
https://www.plastifab.com/how-to/how-to.html
https://www.plastifab.com/how-to/continuing-education.html
https://www.plastifab.com/products/products.html
https://www.plastifab.com/solutions/residential/residential.html
https://www.plastifab.com/solutions/commercial/commercial.html
https://www.plastifab.com/solutions/commercial/commercial.html#