hello, I am not sure if this is available in your country but here for damped surrounding coming from the floor we use simple Styrofoam and/ or ventilation of the room of course. Please note that with dry air the moist itself disappears if it has not been there for too long time.
Fungi is caused my too much moisture in the air. If the cold and wet comes up from the walls, then there is a oil based product that you need to cover the walls with, for your local brand you should ask your dealer. For much more information on fungi and moist, please visit www.roquevalente.com/deckstain.htm