3 in. x 4 ft. x 8 ft. Styrofoam ST-100 Square-Edge Insulation Board, Gray | FMX3.0-25-48SE-DUP

Dupont's 3 in. x 4 ft. x 8 ft. Styrofoam ST-100 Square-Edge Insulation Board, Gray is built to handle structural demands with a 25 psi compressive strength rating, making it suitable for under-slab and load-bearing applications. The square-edge profile allows for tight seams and straightforward installation, helping create a continuous insulation layer. Lightweight yet durable, it is easy to cut and position on the jobsite, making it a practical choice for contractors focused on performance, efficiency, and long-term building envelope protection.

• Closed-cell extruded polystyrene construction provides consistent thermal resistance and moisture control
• 25 psi compressive strength supports use in load-bearing and under-slab insulation applications
• Square-edge design allows tight joints and efficient installation on flat surfaces
• Lightweight board structure makes handling, cutting, and placement easier on the jobsite
• Suitable for use in walls, foundations, and below-grade insulation systems