Typical Bulk Insulation Materials

Bulk Insulation: Batts and Blankets

Glasswool (fiberglass)

• Easy installation,
• Should be protected from moisture,
• Ends and edges are to be butted together to avoid any gap,
• Blankets are used in rolls for under roofs (cathedral, raked ceiling and flat roof),
• Blankets are thinner and denser than batts and may come with reflective foil attached to one side,
• Made from melted glass spun into a mat of fine fibres,
• Can cause irritation, wear protective clothing during installation.

Rockwool

• Higher R value per unit thickness than Glasswool,
• Better Sound absorption,
• Made from melted volcanic rock spun into a mat of fine fibres.

Polyester

• No known physical or health hazard,
• Does not burn but will melt if exposed to a direct flame at high temperature,
• Made from polyester threads spun into a mat, produced in rolls and batts
• Similar physical properties to fibreglass and rockwool
• Should not be compressed or moistened

Bulk Insulation: Boards  (Used mainly in walls and cathedral ceilings)

Extruded Polystyrene

• Rigid and waterproof boards,
• High Compressive Strength,
• High R value per unit thickness,
• Generally more expensive than bulk insulation,
• May come with reflective foil,
• High R-value per unit thickness, suitable where space is limited
• Easy to cut and install and can be rendered

Foil-Faced Expanded Polystyrene

• Rigid boards of polystyrene beads with reflective foil attached to both sides,
• Should be installed with foil facing still air spaces of at least 25mm width to maximise R value,
• Lower R value per unit thickness than Extruded Polystyrene