I have owned a new build house since August of last year. There is a balcony on the second floor and the ceiling of it is below my third floor. The side of the house has HardyPlank siding. Since last year I have noticed something dark on the ceiling which looks like mold or mildew. I also live in hot and humid Houston. I noticed that my neighbors do not have this, although I do not know if they just clean it. Is this normal or do I have a problem of moisture getting between the floor of the third story and the balcony ceiling? I’ve attached a picture of what is looks like. Thanks!