ᐅ Mold in the roof structure discovered before final inspection. What now?

Hello,

we were actually about to complete the handover of our single-family house. However, we discovered mold throughout the entire roof structure. The screed was poured at the beginning of December and cured until January – unfortunately with the roof hatch not fully closed, allowing moisture to rise upwards. The insulation wool at the base of the roof is definitely wet (height approximately 1m (3 ft)), but we do not know how far the water has traveled downward. On the floor and on all the roof beams there is black mold, especially in the flat roof dormer. The construction company (turnkey) simply removed the mold with bleach and a brush (at least in the areas they could reach and see). A building expert has been involved and the first appointment with BTU has already taken place. Both agree that the roof must be opened at least in one spot and that the infestation is severe. (Samples have not yet been taken).

Has anyone experienced something similar? What measures were taken?

Best regards
LunaBluna

The screed should only be installed once the ceiling is sealed with a vapor barrier to the extent that the insulation wool cannot become fully saturated. We were once told that insulation wool that has gotten wet even once cannot be reused and must be replaced. In my opinion, since this is a fault on the part of the contractor, they must repair the defect at no cost to you. Having a building expert involved is definitely helpful to document everything precisely. I would not be satisfied with anything less than complete removal and replacement.

If these are spores (in the case of black mold), they can penetrate deep into the beams. Once introduced, spores are difficult to eliminate. Superficial cleaning with alcohol, for example, might remove some, but the spores have likely already penetrated the material deeply, requiring special measures.