I'm trying to install a new ceiling fan in my condo. I've cut a whole in the drywall to find a broad metal sheets are in my ceiling. I would appreciate help in figuring out what this is and if I can screw the fan fixture into it.
Here's a picture .At the bottom of the picture is a ~1 inch tall I beam. Above that is a broad flat metal sheet with recessed strips perpendicular to the I beam. It looks like the sheet is several feet wide before another recessed strip on the other side. There appear to be several of them running in parallel along the width of my condoceiling. Also, when I knock on them, they don't sound hollow (but I could be wrong about that).
Please let me know if you have any questions.