PU Foam: The Complete Insulation Guide for Builders

Polyurethane (PU) foam has become one of the most popular insulation materials in modern construction. This guide covers everything builders need to know about selecting and applying PU foam.

Why PU Foam?

PU foam offers several advantages over traditional insulation materials: - Excellent thermal insulation (lambda value as low as 0.025 W/mK) - Superior acoustic insulation - Gap-filling capability for irregular shapes - Moisture resistance - Strong adhesion to most building materials

Types of PU Foam

1. One-Component Foam: Cures with moisture from the air. Most common for construction applications. 2. Two-Component Foam: Faster cure, independent of humidity. Used for industrial applications. 3. Gun-Grade vs. Straw-Grade: Gun-grade offers better control and is preferred for professional applications.

Application Best Practices

• Shake the can thoroughly before use (at least 20 times)
• Moisten substrates for better expansion and curing
• Apply from bottom to top for vertical joints
• Fill only 50-70% of the cavity (foam continues to expand)
• Protect from direct sunlight after application
• Trim only after full curing (usually 24 hours)