The Content Of The Article:

Glass wool is the most used insulation today. It is very popular for its thermal insulation capabilities as acoustic but it has some disadvantages to take into account.

Insulation with glass wool

Insulation with glass wool

Glass wool: presentation

Glass wool is one of the mineral insulation materials. Given its high insulation power and its attractive price, glass wool equips 75% of French homes, it is also the most used insulation material in the world. She is made of extruded silica: its manufacture is carried out by fusion and fiber drawing of sand, mineral, cullet or recycled glass. Glass wool is marketed in the form of rolls, smooth and rigid panels very resistant or flakes, used according to the expected level of isolation and the accessibility of the part to be isolated.

Glass wool and efficient both at the level of thermal insulation that of sound insulation. Like all mineral wools, glass wool is noncombustible by nature, so it also represents good fire protection.

Performance of glass wool

Thermal conductivity, also called lambda, of glass wool varies between 0.030 W / m.K and 0.040 W / m.K.

Example of thermal resistance:

  • For a thickness of 100 mm, the thermal resistance R will be between 2.50 m².K / W and 3.30 m².K / W.
  • For a lambda glass wool of 0.035 W / m.K and a thickness of 240 mm, R = 6.85 m².K / W
  • For a glass wool with a thickness of 300 mm and a lambda of 0.040 W / m.K, R = 7.50 m².K / W.

Glass wool does not absorb moisture from the air. If it is accidentally wet (rain or snow for example), simply let it dry, without handling or compressing it. Once dry, it will recover all its insulation capabilities.

The advantages of glass wool

  • Very good thermal insulation: isolates cold and warm
  • Very good sound insulation
  • Thanks to its different shapes (rolls, plates or flakes) it adapts to all environments
  • Material fire retardant (does not catch fire and does not emit toxic fumes)
  • Rodent resistant
  • Long life (about 50 years, maintenance free)
  • Very affordable price

The disadvantages of glass wool

  • Carcinogenic risks suspected (but not proven)
  • Irritant for eyes and skin (wear a coverall, mask and gloves when laying)

The price of glass wool

Count around 10 € the m² for a glass wool with a thickness of 100 mm.


Video Instruction: High Temperature Insulation | Glasswool | Ceramic Wool | RockWool