Mold Growth on ETICS (EIFS) as a Result of ‘‘Bad Workmanship’’?

ON THE EXTERNAL façades of a housing project, which was completed in autumn, a noticeable biological growth appeared after a short time. As described in [1], especially in the area of the lintels an extended mold infestation could be seen (obvious discolouration). The lintels have not been insulated with expanded polystyrene like the rest of the walls, but with mineral wool. Also mainly circular patterns of the infestation appeared in the middle of the façades. Drill core samples were taken in these places. It turned out that the insulation slabs of expanded polystyrene had not been applied without joints, but that a continuous gap of approximately three millimetres existed between the insulation sheets. The circular patterns of mold infestation are approximately located in the area of the joint crosses where four insulation slabs meet.