Glass wool is a mineral insulation made by spinning molten glass into fine fibres, which are pressed with a binder into mats or boards. The many air pockets between the fibres make glass wool both a thermal and an acoustic insulator.
Application
Glass wool, together with rock wool, belongs to the mineral wool group. It is light, resilient and easy to cut to size. Applications:
- Cavity walls and facades — as retrofit insulation or in new build.
- Roofs and lofts — between rafters and over ceiling joists.
- Internal walls — as infill in metal-stud partitions for sound insulation.
- Pipes and ducts — as thermal and acoustic wrapping.
The thermal conductivity (λ-value) is typically around 0.032–0.040 W/(m·K). Glass wool is non-combustible (fire class A1/A2) and vapour-open. Skin and respiratory protection are advisable when handling it.
Related terms
- Insulation
- Mineral wool
- Cavity wall
- Sound insulation
- Building physics
Want to know more about construction terms? Visit our knowledge base on fredsdiyplans.com.