Mastic

Mastic is used to insulate the inside of the duct to cover the seams. The foam in polyurethane sheets oxidizes by reacting with oxygen in the air and after a while appears as airborne particles. Therefore, to prevent this from happening, the joints formed in the polyurethane channel are insulated with mastic. To do this, water-based mastics are used, which do not create an odor due to the heat in the channel in winter, because oil-based mastics from It creates an odor, so it is noteworthy that the use of water-based masitates is approved.