Hello "Messjogi". Your inquiry was only seen by me today, hence the late response. How did you determine the moisture in the described sense ("quite wet")? Moisture can only be checked or measured; you cannot make reliable judgments based on gut feeling here. If you describe that a black foil was found beneath the insulation layer, then this cannot be a sealing, because otherwise you would not have been able to see the "wet" concrete. It was probably a covering foil, effectively acting as a vapor retarder, to somewhat protect the thermal insulation from moisture. As soon as moisture should penetrate into the insulation layer (this is the described eventuality), this thermal insulation cannot fulfill its functions or only to a limited extent. If the moisture under the black foil originates from the (fresh?) concrete, then this—provided it remains where it is—is completely harmless. According to experience, especially with dense concrete components, the remaining (i.e., not reacted) cement particles will react with the free water over the next few years, whereby a "drying" in the figurative sense will still take place beneath the black foil. My suggestion is this: Take some photos of the construction, especially of the foil layer beneath the insulation, preferably also of the foil thickness (e.g., as a foil fold). Otherwise, the architect’s planning should provide sufficient security in assessing the necessary measures. "No need to panic," as I often say. Or in other words: give the planner a little more trust! --------------------------- Best regards KlaRa