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.

enter image description here

  • 2
    In some multi-floor buildings steel sheeting (sometimes corrugated) is laid and concrete is poured onto it. Your ceiling does not appear to be what is normally termed drywall which is gypsum board. Sheetrock is a trademark name of a brand of gypsum board drywall. Apr 19, 2017 at 21:29
  • I agree with Jim - looks like formwork for poured concrete to me too.
    – brhans
    Apr 19, 2017 at 21:30
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    Stop and patch up the hole. Since you live in an apartment you should not making infrastructure changes like this. Your rental agreement most likely will clearly call out what you are liable for when futzing around with property that does not belong to you. BTW this site is not called diy.apartment.modification.
    – Michael Karas
    Apr 20, 2017 at 2:46
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    Sorry, it's actually a condo, not an apartment (It's my first time owning instead of renting, so I still mix up the words sometimes). I edited the original post to reflect this. I was going to power the fan by running a cable up from a pre-existing electrical box that I'm installing a switch in. I've also added a (hopefully) better picture.
    – TurtleTurp
    Apr 20, 2017 at 16:43
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    @MichaelKaras Rental contracts aside, home does not mean house exclusively.
    – Alaska Man
    Apr 20, 2017 at 20:29

1 Answer 1


The drywall does appear to be screwed to the raised channels such as can be seen at the bottom of the hole.

Jim is correct that this is a structure for supporting a concrete floor, which reduces vibration and noise in apartments. You're going to need to figure out how to run wiring to your fan, and you'll need a surface-mount box of some sort.

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