White coating on the wall

[Galsjo411]

Hi, does anyone know what this could be? It is on the vapor barrier behind the insulation. It was also in some parts of the insulation. It is like "cakes" but when you touch it, it turns to powder, no smell.

 

[Raffe11]

[image] [image] Hi, does anyone know what this might be? It's on the vapor barrier behind insulation and also found in some insulation. It's like "cakes" but when touched, it turns to powder, doesn't smell like anything

When was the house built? Ever had additional insulation? I thought it might be urea foam. Becomes like a powder when it has aged

 

[Galsjo411]

The original house is from the 40s, remodeled in the 70s, with a major renovation in the late 80s. Uncertain when this section was made, but considering it was a type of rockwool that resembled ground insulation, it's probably been a long time. I've been given the same tip but I'm not sure this material was used; it's strange in any case, it doesn't smell and turns into powder when touched.