I am trying to install a garage overhead storage rack. I’ve made my pilot holes and when I was attempting the last pre drill I was not hitting the joist. I used the stud finder so I know I was centered on the joist.

It seems I may have hit metal, in fact I detected metal on my stud finder after the drill bit was not penetrating further. I looked above the ceiling from the attic opening but I do not see any metal obstruction that’s noticeable.

I see where the electrical wires are secured and running and this doesn’t seem to be any interference also. Unless there’s electric running on the bottom of the joist between the ceiling drywall and joist and can’t be seen? However I don’t think that’s code.

Is there metal between the joist and ceiling drywall? I don’t see any metal plate but I’m definitely hitting metal or something that is not the joist/wood and I don’t think it’s a nail or screw but I may be wrong. I’ve used the stud finder further down the ceiling along the same joist and I’ve detected metal (but still no obvious signs to the naked eye).

Can someone tell me what I may be hitting and the possible construction configuration of the ceiling that may answer my question. The other 3 pre drill pilot holes went fine. The last one of course is the failure. I’ve added some pictures below Greatly appreciate the help!

enter image description here

enter image description here

enter image description here

  • use magnet to inspect more, there should not be metal unless where the joist join
    – Traveler
    Feb 26, 2023 at 6:34
  • 1
    I'd be working out exactly where the trouble is, and transferring that measurement to the top of the joist. Then drilling down, to find out if I hit whatever it was. And work out how thick it was too.
    – Tim
    Feb 26, 2023 at 11:54

1 Answer 1


Your drilling into the bottom chord of pre engineered trusses. If you are positive that you hit metal, there may be a splice or mending plate there. Usually those are on the side of the chord, or wrapped around the bottom and sides. There may be a wayward protection plate that was just left by the carpenters since it was inconsequential to them at the time.

You really need to get a look at the exact part of the chord you are trying to drill into from above to verify what is there.

I would also be concerned with the weight being added to those chords. They are usually not designed to carry a lot of weight and may need reinforcing from above, such as 2x4s perpendicular across the top of the chords.

  • Thanks, spelling is by far my weakest skill.
    – RMDman
    Feb 26, 2023 at 13:34
  • 1
    Agree about the loading issue. Perhaps the OP can share what they plan on storing on the racks. Feb 26, 2023 at 15:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.