Thanks for your review of Ceilume's Stratford White Feather-Light ceiling panels. You're right, these tiles are very thin. In fact, that's the very first thing we meniton in our HomeDepot.com listing: "Vinyl panel is surprisingly thin but amazingly strong" But these thin tiles are no lightweight when it comes to performance; they're easy to install, impervious to moisture, don't harbor mold or mildew, and won't sag over time like the old mineral fiber tiles. The Stratford has an NRC of .25 and an R value of .012 by themselves. For increased acoustic and thermal insulation, you can use Ceilume's Soniguard Drop Ceiling Insulation to raise the NRC to .50 and the R value to R-6.0. The International Building Code requires that all HVAC grilles, lights, speakers, etc must be supported by the ceiling grid or the structure above and not the ceiling tiles. Please consult with the Pros at your local Home Depot store for a code compliant way to support an HVAC Grille.