There is 3 layers of drywall on one of our ceiling areas and there is an opening for a heating register. How can I seal off that drywall so that there is no chance of loose drywall or dust falling down. The area right beneath there is where kids play and there is the heating air that will blow past it. Will Spackle stick to the drywall there? Thanks.
assuming the drywall is properly fastened? the simplest fix, is to buy a heat register, they usually have a flange around them about 1 1/2 inch. which would stop ant large pieces of drywall from falling through. typical size about 4x12 inches, and just fasten with screws at each end. as far as dust falling through, simply apply two coats of good quality gloss paint on the exposed drywall, let dry completely between coats to seal it good.
I've done jobs for DuPont that required 3 coats of epoxy on all exposed gypsum, each coat to dry 24 hours between coats. meaning, we'd cut a sheet on Monday, cut all boxes or protrusions for pipes and such, epoxy coat each one, epoxy coat again on Tuesday and Wednesday then could finally hang the sheet on Thursday.
the hole in the duct work look irregular, but air will pass through it. I think you can screw register through drywall right into the sheet metal duct with 2" or 2 1/2" screws. just try to keep screws as straight as possible! if needed? pre drill the holes the same size as the shank of the screw
as always, just my thoughts
take what helps? ignore the rest.