Cutting with insulation saws

Insulation tears rather than cuts under a conventional blade, and a torn edge is a gap. These saws use long blades with coarse, widely-set teeth that clear material instead of packing with it, in patterns matched to soft mineral and natural fibre or to rigid PU board. Three machines cover the range by thickness and weight. The cordless insulation saw is the light one at around 2.2 kg, cuts to 350 mm, and can be worked one-handed — which is what you want in a loft or up a ladder. The 200 mm sword saw handles wood and insulation alike at about 6.5 kg. The 330 mm machine goes deepest, combining a chainsaw's reach with a circular saw's control for thick wood-fibre and PU board. Guide rails, angle stops and parallel fences keep the cut square, which decides whether the next batt sits tight against this one.