Window Installation

Key Takeaways: 

  • Use flexible PU foams to seal gaps between window and door frames for superior thermal and acoustic insulation.
  • Soudal’s range of products support movement in building materials while maintaining airtightness and weather resistance.
  • The ideal setup includes three layers: internal airtight seal, thermal/acoustic insulation in the centre, and external weatherproofing.
  • Designed to prevent drafts, noise transfer, and heat loss around joinery. 

Installing Exterior Joinery 

Modern buildings are constantly shifting, temperature changes, material expansion, and structural movement all impact how window and door joints perform over time. That’s why flexible insulation materials are essential to maintain a consistent seal without cracking or losing adhesion. 

Soudal’s product range delivers long-term performance by combining elasticity with high insulating power. Products such as Flexifoam and Pro Expanding Foam Click & Fix offer a perfect balance of flexibility and strength, allowing the joint to move naturally while preserving airtightness. 

For general installation and filling applications, the range also includes Pro Expanding Foam Genius Gun, Pro Expanding Foam Aerosol and Pro Expanding Foam Gun Grade, all delivering fast expansion, strong adhesion to most building materials, and excellent sound and thermal insulation. 

The three-layer window joint system ensures maximum protection and performance: 

  1. Airtight layer (inside) – prevents warm indoor air escaping.
  2. Insulating core (middle) – PU foam provides superior sound and temperature control.
  3. Weatherproof layer (outside) – shields against rain, wind, and UV exposure. 

By integrating these products, installers can achieve durable, energy-efficient joins that maintain comfort and efficiency over time. 

FAQs

Why is flexibility important in window joint insulation?

Because buildings move, a flexible seal allows for expansion and contraction without cracks or air gaps.

Which product is best for thermal and acoustic insulation?

Flexifoam is specifically designed for window and door installations where flexibility and soundproofing are key.

Can I use these foams on both timber and aluminium frames?

Yes, all foams in the Soudal range adhere well to common joinery materials, including timber, aluminium, and uPVC.

Do I still need to apply an external sealant?

Yes, for full protection, combine PU foam insulation with a weatherproof external sealant to complete the three-layer system.