Permo® therm, from Klober, is a phenolic insulation board with a tongue-and-groove edge profile, integrated vapour roof permeable underlay and self-adhesive strips along laps. The product has been designed for above-rafter insulation and offers the added convenience of combining two roofing disciplines in one product. It can be laid on boarded or un-boarded roofs either from left to right or from right to left and is available in various thicknesses. Suitable for all pitches, boards are accompanied by a range of fittings for ease of installation, optimum thermal performance and airtightness.
By laying over rafters, greater height is provided in the roof space and cutting avoided. Boards are interlocked up the roof slope with the integrated roof underlay
facing upwards. Laps are then sealed by removing the release film from the adhesive strip and after either a single or double course counterbattens are laid in alignment with the rafters. These are simply screw-fixed through the boards to the boards prior to tiling battens being fixed.