Construction-Grade Insulating Foam Board
Atlantic Builders Supply Northeast is Your Premier Distributor for Nudura FlexxBoard in New England!
Nudura®FlexxBoard25 is a rigid foam insulation board that offers enhanced performance at a more affordable price, when compared to XPS (extruded polystyrene) boards. When utilized beneath concrete, FlexxBoard25 creates a strong bond with the concrete, establishing a superior thermal barrier that effectively reduces concrete shifting and heaving.
Designed to prevent frost heaving and cracking in concrete, Nudura Flexxboard serves as an under-slab insulation barrier for footings, sidewalks, and driveways, offering R-4.5 per inch for thermal efficiency.
Benefits
FlexxBoard25 offers many advantages at a lower cost than other rigid insulation boards:
- Energy efficiency
- Helps eliminate frost heaving and concrete cracking
- Increases the structural integrity of concrete in both interior and exterior applications
- Bonds to concrete and will not separate like other foam products
- Moisture-, mold- and mildew-resistant
- Will not rot, deteriorate or degrade over time, sustaining its R-Value
- Environmentally conscious formula uses a smaller portion of petroleum to make compared to other foam products
- Made of non-toxic materials that do not off-gas like other foam products
- Superior dimensional stability assures structure remains tight and energy efficient over life of building
- Acts as sound-deadening, quiet barrier
Nudura FlexxBoard25 is the perfect foam insulation board to use above or below ground:

- Under-Slab Thermal Barrier – When used as a thermal barrier before pouring concrete, FlexxBoard25 bonds to concrete – reducing heat loss and helping to prevent possible frost heaving. It helps extend the life of concrete driveways, sidewalks, patios, basements, shop and garage slabs, and basements.
- In-floor Heating – FlexxBoard25 can be used as a thermal barrier beneath concrete slabs when installing radiant floor heating systems – preventing heat loss to the ground while promoting even heating.
- Perimeter Insulation – When used around the perimeter of a poured concrete or block wall foundation, FlexxBoard25 prevents heat loss. In shallow foundation designs, using FlexxBoard25 around the perimeter of a poured concrete slab will help prevent frost penetration and frost heaves.
- Roof Applications – FlexxBoard25 is an exceptional insulator and fill material for all roofing applications.
Frost Protection that Bonds to Concrete!
Nudura FlexxBoard25 establishes a robust bond with concrete, enhancing the durability and strength of the insulation. This foam material is resistant to rotting or deterioration when exposed to outdoor elements.
In contrast, other colored foam boards are prone to detachment from concrete due to their smooth surface finish. This separation can lead to a reduction in the material’s insulation effectiveness over time, potentially necessitating future concrete replacement.
| Overall Dimension | 48″ x 96″ |
| Density Classification | 2.0 pcf |
| Staple Pull-out Strength | 29 lbs. |
| Thermal Resistance | (R-Value) @ 75º 2 inch = R-9 |
| Strength Properties, minimum | psi – 32.8 |
| Compressive Strength | 47 |
| Flexural | 2.0 |
| Dimensional Stability | 24.0 |
| Oxygen Index | .232 |
| Thermal Conductivity | K Factor@ 75º F |
| Moisture Resistance, Maximum | perm./in. – 2.65 |
| WVT (water vapor transmission) | % – 2.4 |
| Absorption (vol.) | – |
| Capillarity | none |
Call today to place your Nudura FlexxBoard order! 603-427-5001