Can Insulation Board Get Wet?

Foam board insulation products are generally considered water and mold resistant but expanded polystyrene foam boards (EPS) have air bubbles that can collect moisture and become wet.

Is it OK for insulation board to get wet?

EcoTherm PIR insulation boards are rigid in nature and a closed cell material, meaning water absorption is minimised. ... Other common types, such as mineral fibre batts, are not generally recommended as they can remain wet several months after exposure to flood water which slows down the wall drying process.

Is foam board insulation waterproof?

Technically, EPS and XPS rigid foam board insulation are considered to be water-resistant. A product branded as waterproof means that it offers complete impermeability, even if permanently immersed in water.