Owens Corning

High-Performance Rigid Foam Insulation

Why choose foam board insulation?

Owens Corning® FOAMULAR® & FOAMULAR® NGX® 250 Extruded Polystyrene (XPS) Rigid Foam Insulation is a closed cell, highly moisture-resistant foam board insulation well suited to meet the needs for a wide variety of residential and commercial building applications.
This XPS foam board is used for above- and below-grade uses such as cavity walls, precast concrete, foundation walls, and under-slab insulation.

NGX Foam Board Insulation Features:

  • Easy to cut, shape, and install for precise fit
  • Reduces Global Warming Potential (GWP) by 80%
  • Provides consistent thermal performance with R-values from 4 to 20
  • Available in thicknesses from 0.75" to 4"
  • Certified for sustainability and performance


Download Data Sheet

Find FOAMULAR® NGX® online and in stores near you

Tailored for ease of use, FOAMULAR® NGX® panels are lightweight, easy to cut, and fit seamlessly into various home renovation projects, making them ideal for both DIY enthusiasts and professional contractors. With various R-values and thicknesses, homeowners can find the perfect fit for their insulation needs, ensuring comfortable, energy-efficient living spaces. The NGX® line further emphasizes sustainability with a reduced Global Warming Potential aligning with home improvement goals. From retrofitting historic homes to insulating modern designs, FOAMULAR® NGX® panels have been integral in a variety of projects, demonstrating their adaptability and performance in real-world settings.

Specifications & Literature

Building Enclosure Solutions

Owens Corning® Enclosure Solutions offers one of the largest portfolios of commercial insulation products for walls, roofs, and below-grade foundations. Engineered with Owens Corning technical expertise and supported by Building Science, Owens Corning® Enclosure Solutions deliver buildings that perform without compromising design.

View Enclosure Solutions

Certifications

Energy Star

Energy Star

NGBS Green Certified

NGBS Green Certified

SCS Recycled Content - Average 20%

SCS Recycled Content - Average 20%

UL Greenguard EPD

UL Greenguard EPD

performance attributes

FOAMULAR® NGX® XPS foam board offers high moisture resistance—up to 13 times more than EPS insulation—making it ideal for damp environments such as basements and foundations. Designed for long-term durability, this NGX insulation complies with ASTM C578 and withstands design loads with minimal deformation while maintaining structural integrity. This rigid foam insulation retains at least 90% of its R-value over time, helping maintain consistent thermal comfort in residential and commercial applications. FOAMULAR® NGX® 250 combines these benefits with compressive strength, making it a reliable choice for demanding insulation needs.

Moisture Management icon

Moisture Management

Durability icon

Durability

Thermal Comfort icon

Thermal Comfort

Resources

Installation Instructions: ResidentialComplete™ Wall Systems
Installation Instructions: ResidentialComplete™ Wall Systems

Technical Information

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

Property

Test Method5

Value

Thermal Resistance6, R-Value (180 day) minimum,
hr·ft2·°F/Btu (RSI, °C·m2/W) @
75°F (24°C) mean temperature



ASTM C518

5.0 (0.88)
@ 40°F (4.4°C) mean temperature5.4 (0.95)
@ 25°F (-3.9°C) mean temperature5.6 (0.99)

Long Term Thermal Resistance, LTTR-Value7, minimum
hr·ft2·°F/Btu (RSI, °C·2/W)
@ 75°F (24°C) mean temperature

CAN/ULC S770-03

5.0 (0.88)

Compressive Strength7, minimum psi (kPa)

ASTM D162125 (172)

Flexural Strength8, minimum psi (kPa)

ASTM C20350 (345)

Water Absorption9, maximum % by volume

ASTM C2720.30

Water Vapor Permeance10, maximum perm (ng/Pa·s·m2)

ASTM E961.5 (86)
Dimensional Stability, maximum % linear changeASTM D21262.0

Flame Spread11,12

ASTM E8410

Smoke Developed11,12

ASTM E84175

Oxygen Index11, minimum % by volume

ASTM D286324
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.

Applications

This foam board insulation is practical for various applications, from attics and basements to foundations and walls. It provides durable insulation for residential and commercial buildings. This NGX foam board can also function as a weather-resistant barrier when joints are sealed. For low-slope roofing applications, Owens Corning recommends FOAMULAR® NGX® THERMAPINK® 25 or FOAMULAR® NGX® 400/600/1000 XPS insulation instead.

  • Basements
  • Foundations
  • Walls

Contact Us

Even though we’re a global company, we’re always ready to answer your questions. Call to speak with an Owens Corning representative.