I am trying to put some anchors into the drywall so I have something to bracket a bookcase to. They don't have to hold much weight, just stop it from swaying during an earthquake.

I've tried several spots, and whatever I use (nail, drill) goes through the drywall at the rate you'd expect, and then after about 3/4", BAM, hits a sudden resistance.

Since I've already mapped out the studs I'm not sure what I'm hitting here...

Below is what I know:

  • 4th floor, apartment
  • Other side of wall is unknown, though, could be bathroom.
  • Building re-built in the last 16mos due to fire.
  • Stud finder indicates studs, though not consistently. They appear to be 16" apart.
  • The four blue tape marks in the center are areas where the stud finder indicated.
  • Additional images at: http://imgur.com/a/FrEyc

enter image description here

  • 1
    3/4" from the surface, or from the back of the drywall? Surely there's some indication of what you're hitting on the drill bit or in the feel of the hammer. What can you tell us?
    – isherwood
    Commented Aug 30, 2017 at 20:48
  • 1
    @isherwood 3/4" from the surface of the drywall. The object behind it appears soft, and the color of wood. But that begs another question, why would there be wood in all of these areas?
    – dameshgarm
    Commented Aug 31, 2017 at 0:46
  • 1
    There are many reasons why extra lumber may be present--structural, mechanical, electrical. If you find wood, it's a safe bet that it's something you can mount to for a depth of 1-1/4" or so. Also, begging the question isn't what you think. I like "raises the question". :)
    – isherwood
    Commented Aug 31, 2017 at 13:10

2 Answers 2


As it turns out, the reason all holes in this wall were running into something beyond the drywall is soundproofing.

The back of the drywall is laminated with another wood-like material to reduce sound-transfer since another apartment shares this wall.

It is safe to drill through, and beyond it is the normal insulation-filled void you would expect.

Can make studfinders have difficulties though.

  • How did you end up finding this out? Commented Sep 3, 2017 at 16:13
  • 1
    @user7374453 The theory came from a friend in construction, and I followed up with the property manager who confirmed this.
    – dameshgarm
    Commented Sep 4, 2017 at 2:21

It's possible you are hitting a nailer plate that protects the plumbing or electrical in that spot. If you drill through it you could be in for a surprise and an expensive repair bill.

Try further to the right or between the other two studs to see if you can get through easily with a finish nail like in your pictures.

Good luck!

  • Nailer plate occurred to me after searching through the other questions, but that would only be on the stud, no? You can see in my attempts I'm trying both in areas where there should and shouldn't be a stud.
    – dameshgarm
    Commented Aug 31, 2017 at 0:50
  • 1
    It could be horizontal wood blocking installed to protect the refrigerant lines going to the air conditioner.
    – Mark
    Commented Aug 31, 2017 at 10:14
  • Normally it would be on a stud. But they may have a plumbing vent stack in the void they are trying to protect.
    – ArchonOSX
    Commented Aug 31, 2017 at 11:10

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