BEKO 1K PU Mounting Foam with Straw Adapter 500 ml Can, Moisture-Curing, B3 Fire Class, Thermal & Acoustic Insulation

With a free foam yield of up to 30–40 liters from a single 500 ml can, this BEKO mounting foam delivers exceptional coverage for sealing, filling, and insulating tasks. The 1-component polyurethane formula cures by reacting with ambient moisture, forming a robust, water-resistant foam that bonds firmly to concrete, masonry, stone, wood, plastics, and metal. Supplied with a practical straw adapter for precise manual application, it is ready to use straight from the can—no special gun required.

Overview

BEKO 280500 is a professional-grade 1K PU mounting foam designed for a wide range of construction and renovation jobs. It expands on application to fill irregular gaps, cracks, and cavities, then cures to a semi-rigid foam with excellent thermal and acoustic insulation properties. The foam is paintable and plasterable once fully cured, allowing seamless integration into surrounding surfaces. Its moisture-curing mechanism ensures reliable performance even in challenging environments, while the B3 fire classification (DIN 4102-1) defines it as normally flammable, suitable for standard building applications where no special fire rating is required.

What stands out

• High expansion: up to 30–40 liters of cured foam per 500 ml can, maximizing coverage per unit.
• Versatile adhesion: bonds strongly to concrete, masonry, stone, wood, various plastics, and metal.
• Moisture-curing 1K PU formula: no mixing needed; cures by reacting with humidity in the air.
• Excellent insulation: reduces heat loss and sound transmission, improving energy efficiency and comfort.
• Paintable and plasterable: once cured, the foam can be finished to match the surrounding surface.
• Includes straw adapter: enables precise manual application into narrow gaps and joints without a foam gun.
• Water-resistant when cured: suitable for use in damp environments, though UV protection is required for outdoor exposure.

Technical details

• Product type: 1-component polyurethane (PU) mounting foam
• Volume: 500 ml can
• Application: manual with straw adapter
• Base material: polyurethane
• Fire class: B3 (DIN 4102-1, normally flammable)
• Curing system: moisture-curing
• Foam yield: up to 30–40 liters (free foamed)
• Temperature resistance (cured): -40°C to +90°C
• Processing temperature (can): +5°C to +30°C
• Surface temperature: +5°C to +35°C
• Tack-free time: approx. 8–12 minutes (at 20°C, 60% RH)
• Cuttable time: approx. 30–45 minutes (at 20°C, 60% RH)
• Full curing time: approx. 24 hours
• Adhesion: excellent to concrete, masonry, stone, wood, various plastics, metal
• Insulation properties: excellent thermal and acoustic insulation
• UV resistance: limited; protect from direct sunlight
• Water resistance: water-resistant once cured
• Paintability/plasterability: yes, once cured
• Colour: yellowish

Our verdict

For professional builders and DIY enthusiasts alike, the BEKO 280500 mounting foam offers outstanding value. Its high expansion rate, strong adhesion, and ease of use with the included straw adapter make it a dependable choice for sealing windows, doors, pipe penetrations, and more. While it requires protection from UV light in exposed outdoor applications, its thermal and acoustic insulation performance is a clear advantage for energy-conscious projects.