Celotex Isover

ISOVER Timber Frame Batt 40

ISOVER Timber Frame Batt 40 is a glass mineral wool batt providing thermal performance and acoustic benefits in timber frame walls. Supplied in a range of thicknesses, the strong, resilient and flexible batts are 570mm wide to fit between standard timber studs. It can also be used as the insulation between the joists in flat roofs.

Product Image
U-value Calculator
Start your U-value calculation >
Use the calculator


  • Timber Frame External Walls – Between The Studs
  • Timber Frame Internal Walls – Between The Studs
  • Timber Frame Separating Party Walls – Between The Studs
  • Flat Roofs - Between The Joists

Product Features

  • 570x1175mm glass mineral wool batts
  • Manufactured from up to 75% recycled content
  • Achieves an A+ generic rating within the BRE Global Green Guide
  • Achieves Eurofins Gold certification, the highest accreditation for indoor air quality

Product Properties

  • Board / Roll size: Width 570mm, Length 1175mm
  • Thickness : 90-140mm
  • Material: Glass mineral wool

Product Performance

  • Lambda: 0.040 W/m.K
  • Reaction to Fire: Euroclass A1 Reaction to Fire classification, according to EN 13501-1

Product Benefits

  • Helps to reduce heat loss within the building envelope and decrease energy costs
  • Reduces the transmission of airborne sound, helping to improve the acoustic comfort of those living or working within the building
  • Non-combustible – achieves Euroclass A1 Reaction to Fire classification
  • Easy to install – push fits between 600mm timber stud centres with no need for cutting or additional fixings
  • The strong resilient and flexible slabs knit together when tightly butt jointed eliminating gaps that could compromise performance
  • Any off-cuts can be reused, minimising waste on site