Measure you house externally as most insulation companies when quoting make the allowances for walls and joists. Then check the distance between ceiling joists or wall studs before purchasing your batts. Measure from the centre of one timber joist/stud to the next. For 450mm spacing use 430mm wide batts, for 600mm spacing use 580mm batts for 900 spacing use two 430 side by side.

WHAT YOU NEED

    * A sharp knife & cutting board
    * Kneeling board (to span at least two ceiling joists)
    * Lighting (if required)
    * Gloves (recommended if glasswool)
    * A dust mask (recommended )
    * Most cost effective way to Insulate
    * Goggles (recommended if working overhead)