Soudal Expanding Foam

Understanding Soudal Expanding Foam

Soudal Expanding Foam is a moisture-curing polyurethane system designed to fill irregular gaps, cavities, and joints with high-density insulating material. The range is engineered to offer superior adhesion to common building substrates, including masonry, timber, and metal, while providing significant thermal and acoustic benefits. These foams expand upon application to create an airtight seal that prevents draughts and reduces noise transmission.

The inventory covers specific performance requirements, from standard gap filling to advanced fire safety. Fire-rated options, such as the B1 and B2 Fire & Acoustic foams, are essential for passive fire protection, offering up to 4 hours of fire resistance depending on the joint configuration. For areas subject to structural movement or vibration, the Flexible Expanding Foam provides high elastic recovery, ensuring the seal remains intact without cracking. The patented Genius Gun applicator is also featured across several products, offering a re-sealable, single-handed solution that reduces material waste.

Material Range

• General Purpose Foams: High-yield polyurethane foams for non-fire-critical applications, featuring B3 Hand Held and Gun Grade variants for versatile gap filling.
• Fire & Acoustic Solutions: Performance-led foams designed for safety-critical installations, including B1 and B2 Genius Gun, and B2 Fire Rated (Gun Grade and Hand Held) options.
• Specialised Performance Foams: Targeted solutions for specific site challenges, featuring Flexible Expanding Foam for movement joints and Genius Gun Gap Filling for precise void closure.

Performance Benefits

• High Thermal Insulation: Effectively reduces heat loss through building envelopes by sealing voids and penetrations.
• Superior Acoustic Rating: Significantly dampens airborne noise, with many products achieving high decibel reduction in tested joints.
• Dimensional Stability: Formulated to minimise post-expansion and shrinkage once cured, ensuring long-term seal integrity.
• Excellent Adhesion: Bonds securely to almost all construction materials, excluding PE, PP, and PTFE.
  
  

Typical Applications

• Window and Door Installation: Sealing the perimeter of frames to provide thermal insulation and acoustic dampening.
• Service Penetrations: Filling gaps around pipes, ducting, and electrical conduits to maintain airtightness and fire compartmentation.
• Cavity Sealing: Filling large voids in wall partitions, roof joints, and floorboards to eliminate draughts.
• Movement Joints: Using flexible formulations to seal joints in timber-frame or high-vibration environments.
  
  

Specification & Standards

• BS EN 1366-4: Fire resistance tests for service installations (Linear joint seals).
• DIN 4102-1: Fire behaviour of building materials and elements (Classifications B1, B2, and B3).
• BS EN 17333: Characterisation of one-component foam (Mechanical strength and expansion properties).
• ISO 717-1: Rating of sound insulation in buildings and of building elements.
  
  

Related Materials and Construction Uses

Soudal Expanding Foam is often used as a primary filler before being finished with other materials. Once fully cured, the foam can be cut, sanded, and plastered or painted to match the surrounding surface. For fire-rated applications, it is frequently used alongside intumescent sealants to ensure a complete fire-stop system. In window installations, it integrates with airtightness tapes and membranes to meet modern building energy standards.