bobco

I think I goofed up on sending this reply. What I meant to do was reply to the three replies I got, as follows: Thanks Tim, Mike, and Scottpat. I’ll start by answering your questions. The A/C ducts are insulated but they are cool to the touch, and that is where the warm moist air is condensing. The subfloor is insulated with the barrier side up. The house is twenty years old. Tim, I will take your suggestion to replace the barrier. And Mike, I’m glad to learn the barrier material is cheap. Could someone suggest the kind of places that would sell it, and tell me what to ask for? Is it just 6mm thick plastic? I saw the online ad by basementsystems.com and theirs looks like a special multi-layer composition. I’ll be 84 in another month but I think I can handle that vapor barrier job you described. I might invest in a pair of kneepads though. Is the mastic used to stick the plastic barrier to the foundation blocks? The Advanced Energy book that was mentioned says to mechanically fasten it to the walls. What does that entail? Nailing it? They also say to leave a 3â€

I have wet insulation and some water on the floor. It is from condensation on the air conditiong ducts, not leakage. We have hot, moist summers here in NC. I am an engineer but no expert therefore I have read many forums on this topic to acquaint myself with it. My question is this. Would I get a drying out of the space if I sealed the vents and used an exhaust fan in one of the vent openings? This would create a small negative pressure in the space, drawing some conditioned air from the house. It would also blow off any radon there might be. Would this avoid the high cost of putting down a new vapor barrier. My original one is torn and parts are missing. I would like to hear from you (youse) on the pros and cons of this idea.