Dupont XPS 250 Blue Board is a nonstructural, rigid insulation board made from Extruded Polystyrene Foam (XPS). It’s designed for builders, remodelers, and DIY enthusiasts who want a continuous insulation barrier on exterior and interior walls, with up to 20% higher effective R-values.

First manufactured in 1941, Dupont's blue colored extruded polystyrene has been an industry leader ever since. Extruded Polystyrene Foam offers high, long-term R-value and excellent compressive strength. Blue Board's closed cell structure and lack of voids resist moisture penetration thus increasing its thermal efficiency and protecting underlying materials from water damage. When used with Weathermate construction tape to cover seams and Great Stuff sealants to seal gaps, Dupont STYROFOAM™ insulation board provides a barrier against air leakage and infiltration.

Key Features & Design

• Residing Board - Use over existing siding as an underlayment for new siding.
• Residential Sheathing - Use over plywood or OSB sheathing as an underlayment for siding.
• Tongue and Groove Insulation - Use on foundation walls or interior basement walls.
• Edge treatment - Edge treatment helps boards fit snugly against each other.
• Scoreboard - Scored Square edge insulation board scored on 16" and 24" centers making it easy to snap into convenient widths.
• Sqft/Pack - 32
• Use - STYROFOAM™ Brand Scored Square Edge Extruded Polystyrene Foam (XPS) Insulation helps protect foundation dampproofing and waterproofing, especially during backfilling. It also provides a secondary barrier against groundwater leakage.
• Foundation Protection - With STYROFOAM™ Brand Scored Square Edge Insulation, freeze-thaw cycling of the foundation wall is minimized, reducing the potential for cracking.
• Condensation - And a warmer foundation can reduce the potential for condensation.
• Applications - STYROFOAM™ Brand Scored Square Edge Insulation can be used against commercial interior walls and exterior foundation walls in above- and below-grade applications.
• Under Slab - STYROFOAM™ Brand Scored Square Edge Insulation can be used under the slab or over the deck or subfloor.
• Soil Compatibility - STYROFOAM™ Brand Scored Square Edge Insulation is suitable for use in pervious, semi-pervious, and practically impervious soils.

Shipping note: We cannot ship to the following states: California, Colorado, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Vermont, Virginia, Washington.