Spray cork adheres to most building surfaces, including brick, concrete, plaster, metal, timber, and some roof materials, offering eco-friendly insulation that reduces energy costs while managing moisture effectively.
Spray cork offers a versatile, eco-friendly insulation solution for homeowners and building professionals looking to improve thermal performance and reduce energy costs. This natural material provides benefits beyond traditional insulation while working across numerous surface types for both interior and exterior applications.
Key Takeaways
- Spray cork provides thermal insulation for various surfaces, including walls, roofs, and floors, while requiring minimal space compared to traditional insulation methods.
- Proper surface preparation is crucial for adhesion; surfaces must be clean, dry, and structurally sound before application.
- While versatile, spray cork should not be applied to wet surfaces, unstable substrates, or silicone-rich coatings without proper remediation.
What Spray Cork Is and Why It’s Different
Spray cork is a natural insulation material made from cork granules harvested from the bark of cork oak trees. Unlike traditional insulation that often requires significant space and structural adjustments, spray cork forms a thin layer (typically 2-4mm) that can be directly applied to various surfaces.
The material offers impressive thermal properties with thermal conductivity values between 0.037–0.045 W/m·K. This natural product is breathable yet water-resistant, making it particularly suitable for UK buildings where managing moisture is crucial.
Spray cork stands apart from conventional insulation methods through its versatility. While traditional solutions might require removing fixtures or losing valuable space, spray cork can be applied to existing structures with minimal disruption.
Where Can You Apply Spray Cork? (Surface-by-Surface Breakdown)
Spray cork’s adaptability makes it suitable for numerous applications across residential, commercial and industrial buildings.
Wall Surfaces
Exterior Walls: Spray cork adheres excellently to most mineral substrates commonly found in UK buildings. Brick, concrete, blockwork, and traditional render (both cement and lime-based) make ideal surfaces after proper cleaning and preparation.
For painted façades, spray cork can be applied if the existing coating is firmly bonded and not chalking or blistering. However, elastomeric or silicone-rich paints may need removal first, as they can impede adhesion.
Stone masonry requires special consideration. While spray cork works well on many stone surfaces, highly moisture-sensitive stones need careful assessment to ensure the entire wall assembly remains vapour-open.
Interior Walls: Inside your home, spray cork performs well on plaster, plasterboard, skim coats, lime plaster, and interior blockwork. These surfaces typically need standard preparation like filling, sanding, and ensuring they’re dust-free.
A significant benefit for interior applications is that spray cork helps moderate surface temperatures, reducing cold spots and the risk of condensation that can lead to mould growth.
Roof Applications
Spray cork offers excellent solutions for various roof types, though application methods vary depending on the roof structure.
- Flat Roofs: Certain flat roof systems allow spray cork as a protective weathering layer. Bituminous felt and some liquid waterproofing systems are compatible, though you should always verify compatibility with the roof waterproofing manufacturer.
- Pitched Roofs: On pitched tile and slate roofs, spray cork can provide additional weather protection and some thermal benefit. The material’s flexibility makes it suitable for the varying angles and surfaces found in pitched roof construction.
- Conservatory Roofs: Spray cork excels on conservatory roofs, helping regulate temperature year-round. It reduces the greenhouse effect in summer while improving heat retention in winter, making these spaces more comfortable and usable.
Floor Systems
Concrete slabs and timber floor structures can both accept spray cork applications, though preparation requirements differ significantly.
For concrete floors, ensuring the surface is clean, dry, and free of contaminants is essential for proper adhesion. A moisture barrier may be required in some cases.
Timber floors need to be stable and dry before application. The cork’s breathability works particularly well with timber, allowing natural moisture movement while providing insulation benefits.
Additional Applications
Beyond the major structural elements, spray cork proves valuable for several specialised applications:
- Pipes and Ducts: Spray cork can insulate pipes and ductwork, reducing heat loss in distribution systems. The material conforms well to curved surfaces, providing seamless coverage.
- Tanks and Storage Vessels: Industrial and commercial tanks benefit from Spray Cork’s insulating properties and moisture resistance. The coating helps maintain consistent temperatures inside storage vessels.
- Metal Surfaces: Galvanised steel, aluminium, and powder-coated cladding can accept spray cork when properly prepared. These surfaces require degreasing, abrasion, and appropriate metal primers before application.
Can Spray Cork Be Used Over Asbestos?
Certain spray cork products are specifically formulated and approved for asbestos encapsulation. These specialised formulations create a protective barrier over asbestos-containing materials, preventing dangerous fibres from becoming airborne.
This approach often provides a safer and more cost-effective solution than complete asbestos removal, particularly when the material remains intact and undisturbed.
We provide certified spray cork solutions for asbestos encapsulation that meet UK safety standards and include comprehensive warranties. Our systems create an effective, long-lasting protective layer that helps manage asbestos risk while improving thermal performance.
Where Not to Use Spray Cork
Despite spray cork’s versatility, certain surfaces should be avoided:
- Wet or damp surfaces – Active moisture issues must be resolved before application. Trapped moisture can compromise adhesion and performance.
- Highly unstable substrates – Surfaces with severe structural movement or deterioration require remediation first.
- Greasy or contaminated areas – Oil, grease, and certain chemicals prevent proper adhesion.
- Silicone-rich coatings – These materials impede proper bonding without extensive preparation.
- Friable or crumbling materials – Weak substrates cannot support the coating effectively.
- Glazed ceramics/tiles – Without proper abrasion and priming, these smooth surfaces resist adhesion.
- Areas with ongoing salt efflorescence should also be fully remediated before spray cork application to ensure lasting results.
Preparing Surfaces for Strong Adhesion
Proper preparation is crucial for spray cork performance. Follow these essential steps:
- Clean thoroughly – Remove all dust, dirt, grease, and loose material from the surface.
- Repair damaged areas – Fill cracks, holes, and unstable sections before application.
- Apply appropriate primer – Different surfaces require specific primers to ensure proper adhesion.
- Check moisture levels – Ensure the substrate is sufficiently dry (below manufacturer-specified moisture content).
- Consider weather conditions – Apply in appropriate temperature ranges (typically 5-30°C) and avoid application during rain or high humidity.
For metal surfaces, degreasing and abrasion are often necessary before priming. Timber surfaces require seasoning and stability checks, plus appropriate wood primers.
Testing adhesion on small representative areas is recommended, especially on older or mixed substrates.
Advantages and Limitations by Surface Type
Different surfaces present unique benefits and challenges when paired with spray cork. This comparison helps identify the optimal applications:
| Surface Type | Adhesion Strength | Thermal Performance | Durability | Installation Complexity | Maintenance Requirements |
|---|---|---|---|---|---|
| Brick/Stone | Excellent (with proper prep) | Good thermal moderation | 25+ years | Moderate | Low |
| Concrete | Excellent | Good thermal moderation | 25+ years | Low | Low |
| Plaster / Plasterboard | Very Good | Excellent for condensation control | 20+ years | Low | Low |
| Metal | Good (with primer) | Excellent thermal bridging reduction | 15-20 years | High | Medium |
| Timber | Good | Good thermal performance | 15-20 years | Medium | Medium |
| Roof Membranes | Variable (check compatibility) | Good | 10-15 years | High | Medium |
How Spray Cork Compares to Other Coatings
When evaluating insulation options, it’s helpful to understand how spray cork stands against alternatives:
Vs. Traditional Render Systems: Unlike standard renders, spray cork provides thermal benefits while remaining flexible and resistant to cracking. Traditional renders offer little insulation value but may be less expensive initially.
Vs. External Wall Insulation Boards: External insulation boards provide superior U-values but require significant alterations to external features like windowsills and rooflines. Spray cork offers a less disruptive alternative with moderate thermal improvement.
Vs. Internal Drylining: Internal insulation boards provide better insulation values but reduce room dimensions noticeably. Spray cork preserves interior space while still improving thermal comfort.
Vs. Paint Coatings: Standard paint offers no insulation benefits, while “thermal” paints rarely deliver meaningful results. Spray cork provides verified thermal improvements alongside decorative finishes.
Final Thoughts
Spray cork provides a versatile insulation solution across numerous surface types when properly applied. To discuss your specific project needs or learn which surfaces would benefit most in your property, contact our expert team for a personalised assessment and free quote. We’ll help you maximise the performance benefits while ensuring proper application for long-lasting results.
FAQs
Can spray cork be applied over painted surfaces?
Yes, provided the paint is firmly adhered, not chalking, and compatible with the spray cork system. Elastomeric and silicone-rich paints may need removal before application.
How does spray cork perform on metal surfaces?
With proper degreasing, abrasion, and metal-specific primers, spray cork adheres well to metal. It’s particularly effective at reducing thermal bridging in metal structures.
Does spray cork work effectively in damp-prone areas?
While spray cork is breathable and resistant to surface moisture, it shouldn’t be applied to actively damp surfaces. Address underlying moisture issues first, then apply spray cork to help prevent future condensation problems.
Can spray cork be applied DIY, or is professional installation required?
A professional application is strongly recommended. Certified applicators have the specialised equipment and expertise to ensure proper adhesion, coverage, and finish quality.
Will spray cork affect the breathability of walls?
Spray cork maintains wall breathability, with vapour permeance around 0.58 mg·m⁻²·h⁻¹·Pa⁻¹. This makes it suitable for traditional buildings where trapped moisture could cause problems.
What thickness is recommended for optimal insulation?
Typical applications range from 3-6mm. While thicker applications provide marginally better insulation, spray cork works primarily by improving surface temperatures rather than achieving deep insulation.
