Klober Permo® therm is a tongue and groove insulation board with integrated reflective underlay and self-adhesive edge strips to seal laps.
Unlike square-edged boards, Permo therm has tongue and groove edges which prevent formation of air leakage paths and thermal bridges.
The product is installed over rafters and not only provides added height within the roof space but removes the need for separate underlay installation.
With LABC approval, boards are 80mm thick and can be laid in either direction with no ventilation of the batten/counter-batten cavity needed unless impervious or tight-fitting roof coverings are used.
Permo therm has very low thermal conductivity (λ – 0.021 W / mK) and is therefore more efficient than traditional insulation boards of a similar thickness. It is also CFC and HCFC-free.