I'm trying to figure out what's going on with the joists in my ceiling on the first floor, and I think I might have identified them, but I'd love to get your input! I've attached a detailed image that shows what my stud finder detected and my exploratory nail holes. There seems to be a ~1.75" wide "stud" running the full length of the ceiling, and I found similar spacing every ~16" across the room. Additionally, I discovered metal dots (likely drywall screws) that my magnet sticks to, which you can see in the second picture.
I even drilled slowly into the center of what I think is the joist. I got through the drywall, followed by about 0.75" of a denser material, after which my drill bit went all the way in without more resistance. I then securely placed a ceiling hook in this hole, and it feels solid, with it handling at least 30lbs of force comfortably. I left the hook in place and hung a ~12lb tiffany style lamp from it, keeping it just above the desk for safety. Based on this, do you think I'm dealing with a 50lb rated hook wired into the wood of an i-joist? Is there anything else I should be aware of? Thanks for your help!
2 Answers
It sounds like you’ve probably got a TJI joist there. These are engineered with a top and bottom flange and a web in between. Hanging your 12lb lamp should be just fine; I wouldn’t go trying to hang a swing or heavy shelves from it, though. Just play it safe!
If you're curious about the interior structure, consider using a small fiber optic inspection camera to check out what’s actually going on in there! It just needs a 3/8" hole in the ceiling. This could give you more insight into what you're working with.
I’m a bit worried about the 12lb light fixture. Does it seem like it’s really secure? What if there’s more weight on it later?