Glasswool
Glasswool Insulation
Glasswool Insulation is a high-performance thermal and acoustic insulation material manufactured from recycled glass and sand. It offers excellent R-values, long-term loft stability, and a non-combustible fire rating, making it one of South Africa’s most widely used insulation materials. Glasswool is commonly used in residential, commercial, and industrial applications.
What Is Glasswool Insulation?
- Manufactured from recycled glass, silica sand and binding resins
- Formed into soft, flexible mats or batts
- Naturally non-combustible (A1 fire rating)
- Designed for consistent thermal and acoustic performance
- Lightweight, easy to handle and simple to install
Key Advantages
- Strong thermal resistance for its thickness
- Excellent acoustic absorption for quieter indoor spaces
- A1 fire rating for improved safety
- Stable loft retention — keeps its thickness over time
- Cost-effective across most insulation applications
- Lightweight and flexible for easier installation
- Made using environmentally conscious recycled materials
Where Glasswool Is Used
Glasswool is suitable for a wide range of residential, commercial and industrial projects:
- Ceiling insulation for homes and offices
- Roof insulation under metal and tiled roofs
- Wall cavities in drywall or brick structures
- Acoustic applications in internal partitions
- Industrial roof systems needing non-combustible materials
Glasswool vs Polyester
Glasswool and polyester are both popular, but they perform differently:
- Higher R-values at equivalent thickness
- Better sound absorption due to denser fibers
- A1 non-combustible vs polyester’s B-class rating
- More cost-effective per m²
- Slightly more fibrous during installation
This makes glasswool the preferred option when thermal performance, acoustic control and fire safety are priorities.
For a full breakdown of polyester performance, see → Polyester Insulation
Explore Glasswool Options
These material families fall under the glasswool category:
- Aerolite Soft Touch → Aerolite Insulation
- Knauf Earthwool → Knauf Insulation
- Factorylite → Factorylite Insulation
- Energylite → Energylite Insulation
- Cavitybatt → Cavitybatt Wall Insulation
- Cavitylite → Cavitylite Wall Insulation
- Alucool → Alucool Foil-Faced Insulation
Installation Notes
- Ensure full coverage with no compression or gaps
- Maintain a 50mm clearance around downlights or heat sources
- Lay directly over ceiling boards for best thermal performance
- Store in a dry area before installation
- Suitable for both new builds and retrofits
Why Choose Glasswool
Glasswool insulation provides one of the most effective combinations of thermal resistance, fire safety and acoustic comfort available today. It is reliable, cost-efficient and suitable for a wide variety of South African building types. For homeowners and contractors seeking a well-proven, high-performance insulation material, glasswool remains the industry benchmark.
Where to Go Next
- View mineral wool insulation
- View stone wool insulation
- Browse insulation by material
- Return to insulation overview