You did an excellent job explaining. In fact, the corrugated fiberglass panels are my fall back and I'll probably have to use them. I still am looking for an answer to my original question. Is there a product for this application? I have a neighbor who did beta testing for this application for a manufacturing company, (unknown),and the product, which didn't work so well, looked great and it was installed between the joists. I'm trying to find the upgraded product if there is such a thing or something similar. Thanks for the reply. I appreciate your detail and the fact that you did it twice without failure. Regards__mb