When torching a bituminous base layer onto IKO enertherm BM insulation (which has a bitumen-compatible facing on the top side), it is crucial to direct the flame toward the underside of the bituminous membrane, not toward the insulation board.
The base layer must be fully and evenly torched, ensuring that the bitumen on the underside of the membrane melts and flows properly as the roll is applied.
Additionally, the base layer must always be applied partially bonded, to allow for vapour pressure distribution and to prevent blistering or deformation of the system.
