XPS Insulation



Owens Corning FOAMULAR 250 Extruded Polystyrene (XPS) Rigid Foam Insulation is a closed cell, moisture-resistant rigid foam board well suited to meet the needs for a wide variety of residential and commercial construction applications.

Download Brochure PDF | 6.77 MB

Owens Corning FOAMULAR 250 Extruded Polystyrene (XPS) Rigid Foam Insulation is a closed cell, moisture-resistant rigid foam board well suited to meet the needs for a wide variety of residential and commercial construction applications.

Download Brochure PDF?V=1504850560000 | 6.77 MB

Specifications and Literature

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Product Features

Moisture Management

Exceptional moisture resistance


Excellent long-term stable insulating performance at R-5 per inch

Thermal Comfort



Technical Information

FOAMULAR® 150 and 250 are also available in scored square edge (SSE) configuration, scored at 16" and 24" centers.

Property Test Method2 Value
Thermal Resistance3, R-Value (180 day) minimum,
hr·ft2·°F/Btu (RSI, °C·m2/W)
@ 75°F (24°C) mean temperature
¾" Thickness 4.0 (0.70)
1" Thickness 5.0 (0.88)
1½" Thickness 7.5 (1.32)
2" Thickness 10 (1.76)
2½" Thickness 12.5 (2.20)
3" Thickness 15 (2.64)
4" Thickness 20 (3.52)
@ 40°F (4.4°C) mean temperature
¾" Thickness 4.3 (0.76)
1" Thickness 5.4 (0.95)
1½" Thickness 8.1 (1.43)
2" Thickness 10.8 (1.90)
2½" Thickness 13.5 (2.38)
3" Thickness 16.2 (2.85)
4" Thickness 21.6 (3.80)
Long Term Thermal Resistance, LTTR-Value3, minimum
hr·ft2·°F/Btu (RSI, °C·2/W)
@ 75°F (24°C) mean temperature
CAN/ULC S770-03
¾" Thickness N/A
1" Thickness 5.0 (0.88)
1½" Thickness 7.8 (1.37)
2" Thickness 10.6 (1.87)
2½" Thickness 13.4 (2.36)
3" Thickness 16.2 (2.85)
4" Thickness 22.0 (3.87)
Compressive Strength4, minimum psi (kPa) ASTM D1621 25 (172)
Flexural Strength5, minimum psi (kPa) ASTM C203 75 (517)
Water Absorption6, maximum % by volume ASTM C272 0.10
Water Vapor Permeance7, maximum perm (ng/Pa·s·m2) ASTM E96 1.5 (86)
Dimensional Stability, maximum % linear change ASTM D2126 2.0
Flame Spread8, 9 ASTM E84 5
Smoke Developed8, 9, 10 ASTM E84 45-175
Oxygen Index8, minimum % by volume ASTM D2863 24
Service Temperature, maximum °F (°C) 165 (74)
Linear Coefficient of Thermal Expansion, in/in/°F (m/m°C) ASTM E228 3.5 x 10-5 (6.3 x 10-5)

  1. Properties shown are representative values for 1" thick material, unless otherwise specified.
  2. Modified as required to meet ASTM C578
  3. R means the resistance to heat flow; the higher the value, the greater the insulation power. This insulation must be installed properly to get the marked R-value. Follow the manufacturer’s instructions carefully. If a manufacturer’s fact sheet is not provided with the material shipment, request this and review it carefully. R-values vary depending on many factors including the mean temperature at which the test is conducted, and the age of the sample at the time of testing. Because rigid foam plastic insulation products are not all aged in accordance with the same standards, it is useful to publish comparison R-value data. The R-value for FOAMULAR® XPS Insulation is provided from testing at two mean temperatures, 40ºF and 75ºF, and from two aging (conditioning) techniques, 180 day realtime aged (as mandated by ASTM C578) and a method of accelerated aging sometimes called “Long Term Thermal Resistance” (LTTR) per CAN/ULC S770-03. The R-value at 180 day real-time age and 75ºF mean temperature is commonly used to compare products and is the value printed on the product.
  4. Values at yield or 10% deflection, whichever occurs first.
  5. Value at yield or 5%, whichever occurs first.
  6. Data ranges from 0.00 to value shown due to the level of precision of the test method.
  7. Water vapor permeance decreases as thickness increases.
  8. These laboratory tests are not intended to describe the hazards presented by this material under actual fire conditions.
  9. Data from Underwriters Laboratories Inc.® classified. See Classification Certificate U-197.
  10. ASTM E84 is thickness-dependent, therefore a range of values is given.

Applicable Standards

  • SCS Recycled Content - Average 20%
  • UL Greenguard EPD
  • Energy Star
  • NGBS Green Certified


Steel Framed

FOAMULAR 250 Extruded Polystyrene (XPS) provides continuous insulation over steel stud framing.

Concrete Masonry Unit

FOAMULAR 250 Extruded Polystyrene (XPS) provides continuous insulation in insulated concrete sandwich panel walls, in masonry unit cavity walls, or when used with non-penetrating, surface mounted furring systems over masonry or concrete walls. FOAMULAR 250 retards the transmission of water vapor and moisture in masonry walls.

Below Grade Foundations

Insulates and retains its properties in below grade perimeter and foundation applications, or directly beneath the concrete slab to complement the insulating sheathing envelope around the building framing

eBooks and Guides

Division 7 eBook

The Division 7 Thermal & Moisture Protection eBook is an easy-to-use tool that provides quick access to valuable Division 7 materials including product data sheets, 3-part system specifications, ICC-ES Code Reports and more.

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