Best Draught Proofing & Weatherstripping — PU Expanding Foam (2026)
2 draught proofing & weatherstripping matching material “PU Expanding Foam”, hand-picked from UK Amazon listings.
Not sure which one to pick? Read our Best Draught Proofing & Weatherstripping UK (2026) guide.
This high-performance PU expanding foam offers a robust solution for draught proofing and weather sealing in various applications around your home. Formulated with closed-cell polyurethane, it provides exceptional insulation properties alongside a durable, flexible sealant. The foam expands rapidly when dispensed, filling gaps and cracks effectively to prevent cold air ingress and heat loss.
Ideal for tackling draughts in windows, doors, skirting boards, and other vulnerable areas, this expanding foam creates a tight seal that minimizes energy wastage. Its versatility makes it suitable for both DIY projects and professional applications. The adhesive properties ensure long-lasting performance, resisting movement and maintaining its effectiveness over time.
The product is supplied with a convenient nozzle applicator, allowing for precise application and control. It cures to a firm, resilient finish, providing a protective barrier against the elements. Remember to follow all safety instructions during use – wear appropriate gloves and eye protection.
#1 Pick
Soudal Genius Gun Gap Filler 500ml Expanding Foam- PU Expanding Foam
£8.55
Pros
- Patented Genius Gun applicator allows precise, single-handed application
- High thermal and acoustic insulation seals draughts around frames and pipework
- Well-established trade brand with a strong review track record
Cons
- Expanding foam needs trimming back once cured for a neat finish
#2 Pick
2 x 500ML Gap Expanding Foam Filler PU Expansion Insulation BONDING Filling- PU Expanding Foam
£10.98
Pros
- Twin-can pack covers more draught points than a single 500ml can
- PU foam bonds and insulates in one step around door and window frames
- Useful for roofing eaves, pipe entries and general gap sealing
Cons
- Needs a gun or straw applicator for controlled bead placement
FAQ
What surfaces can PU expanding foam be applied to?+
PU expanding foam is suitable for use on wood, metal, plastic, and dry walls. However, it's crucial to test a small area first to ensure compatibility with the specific surface material.
How long does it take for the foam to fully cure?+
Full curing typically takes 24-72 hours depending on ambient temperature and humidity. Allow sufficient time before applying any finishing treatments or moving furniture around the treated area.
What tools do I need to apply the foam effectively?+
You’ll need a trigger gun for dispensing, a suitable cutting knife or scraper for shaping the cured foam, and gloves for protection. A low-lint cloth is useful for cleaning up any excess foam.
Can PU expanding foam be painted over?+
Yes, it can usually be painted over once fully cured. Use a primer specifically designed for polyurethane to ensure proper adhesion and colour stability.
How much does the foam expand?+
The foam expands by approximately 30-50% of its original volume when dispensed, depending on the application pressure and nozzle setting. Experiment with the trigger gun's settings to achieve desired fill levels.
Is PU expanding foam suitable for external use?+
While usable externally, consider using a specifically formulated exterior grade PU foam for optimal weather resistance and longevity. Regular inspection is recommended.
What safety precautions should I take when using this product?+
Always wear gloves and eye protection to prevent skin and eye contact. Ensure adequate ventilation in the work area and avoid inhaling fumes. Keep away from heat sources and open flames.
How do I clean up excess foam after application?+
Use a solvent-based cleaner or warm, soapy water to remove any uncured foam. Avoid using harsh chemicals that could damage the cured material.
What is the shelf life of the PU expanding foam?+
The product has a shelf life of approximately 12-18 months when stored in a cool, dry place away from direct sunlight. Check the batch code for expiry date information.
Can I use this foam to fill large gaps?+
While effective for smaller gaps and cracks, larger voids may require multiple applications or supplemental filling materials for complete coverage. Consider using a different product for extensive repairs.