The issue depends on the structure of the foam.

Open-cell foam absorbs moisture from the air, but also gives it back. It therefore performs well in rooms where moisture is relatively low, mainly pur foams are used as insulation in single-family housing.

In the case of Crossin Attic Soft foam, the short-term water absorption coefficient is one of the best on the market and is:

Wp ≤ 0,85 kg/m2

In the case of closed-cell foam, it absorbs very little moisture.

For example, the short-term soak factor for Crossin Wall foam is:
Wp ≤ 0,11 kg/m2