Home Repair/Mold Remediation/CONCRETE STAIRWAY

I need this answer within 3 days! I don%26#39;t know how to designate that. My question involves PREVENTION of future mold outbreaks in a concrete stairwell within a home in Chicago, which is obviously known for cold winters and warm summers. I have done some web research on mold prevention and remediation generally, but I have not found the answer to two questions, which are specific to CONCRETE residential construction. Here are the details: I live in the 3rd floor unit of condominium built in the last 18 months. The building is made of poured concrete, and the ceilings are concrete forms. The uppermost units include a rooftop deck, which is accessed by a stairway that is internal to my unit. The walls of this stairway are uninsulated concrete, and it seems they are also not insulated on the exterior. Recently we have discovered serious GREEN GROWTH in this area (which is of course, quite tall), and condensation on the ceiling. The developer%26#39;s proposed solution is to sandblast the current paint, apply something (either a sealant or a special paint?) to the walls, then apply polysterene insulation INTERNALLY. My questions are: (1) is the developer%26#39;s proposed solution likely to work? (proposal=application of some substance, followed by insulation) And must it also include the ceiling? On the other hand, is a much more expensive solution (e.g. exterior insulation) required? (2) More generally, is a %26quot;vapor barrier%26quot; called for in this situation, and, if so, what type? After my amateur research, I was throwing that word around liberally with the developer because it had a nice sound to it (!) and he was nodding his head. But now I%26#39;m not so sure, because the developer%26#39;s theory is that the problem is created not by moisture coming in from outside but internally, simply from warm air from the unit hitting cold air up near ceiling, causing condensation and then mold growth, so I%26#39;m not sure what the v.b. would be keeping out or in. Thanks. MM
If you don%26#39;t like his solution how do you plan on stopping him? Here is what I would do: Let him fix it and see what happens. The water is getting there somehow. You will know very quickly if the problem is solved.
to just4fun2-ga: we will not know very quickly if the problem is solved, because the problem only occurred in winter and we are coming up on spring/summer! Also, if he installs insulation on the inside and then drywall, we will have no idea what is going on beneath it. it%26#39;s not a leak, it%26#39;s the formation of condensation that apparently only occurs in cold weather.
Strikes me that you need some form of ventilation - or a condensor You need to remove the water vapour from the system, not just move it around
to boroughmal-ga: Wow, I am not at all disappointed; I%26#39;m impressed and thankful that you took the time to make your comments. And I%26#39;m glad the contractor knows what he is doing...I just didn%26#39;t want to rely on his opinion.... My only concern is when you say ventilate externally---how oh how, if the walls are solid concrete? Through the roof?