• Hometalker
  • Lawrence, NY
Asked on May 15, 2019

What are these walls made of?

Robyn GarnerMichael McNinneyDiane Coverdale


On the other side of this wall in my apartment is the hallway in my building. When drilling it's solid and I got black dust coming back on 1 hole and then on the hole 2 feet beneath I got reddish dust coming back. Trying to hang twin racks for shelving and thought to use toggle bolts, but I'm unclear as to what it is that I'm drilling into and want to make sure I'm using the right fasteners and the right bit. I put a few items on what the existing hardware was (seems like metal screws with plastic anchors) and the shelf came falling down.


If using toggle bolts, could I reuse the holes?


There are some great links with a lot of info on plaster...



q what are these walls made of
6 answers
  • William
    on May 16, 2019

    Looks like plaster and lath to me. A base coat of cement scratch coat over wood lath and a surface coat of plaster. Yes, use the toggle bolts. Any other anchors will not work. The plaster will just crumble and they will pop out. Just make sure the screws are long to compensate for the thickness of the plaster, cement scratch coat, wood lath, and for the toggle to open. Probably 3" should work

  • Cheryl Williamsen
    on May 16, 2019

    With the colors you were describing, I’m thinking you were drilling into variations of different masonry products.

    For example clay brick, would be red. Concrete block or cement block as it’s called, would be gray or tan.

    I think masonry, because that wall should be a fire-rated wall.

    Toggles or mollies.

  • Diane Coverdale
    on May 16, 2019

    Do you know howold your building is? William maybe correct, but you did say you live in an apartment.Ifthis is an "exterior" wall between the apartments, it maybe fire board. Its a firebreak protection to prevent/reduce the spread in case of fire.

  • Michael McNinney
    on May 16, 2019

    Go to your local home depot or Lowes and buy tap con screws, you will have to rent a roto hammer drill to install them.

  • Robyn Garner
    on May 16, 2019

    It's definitely NOT lathe and plaster. Here are picture of what lathe & plaster looks like under the finish coat.

    It appears that you've got horsehair plaster walls. You must be extremely cautious as there might be asbestos in the plaster and possibly layer(s) of lead paint! If it were me, I'd contact the landlord asap and demand testing for both! AND, I'd move out right now! (Keep track of all the expenses of living outside your place. You can take landlord to Small Claims Court - the monetary limit is usually $10K but call and ask).

    Moving on - you can Google how to properly repair the hole you have. You'll have to remove the loose parts, probably chisel a reverse "v" groove at the edges and use plaster to repair. Lots of sanding, etc. NO, you can't reuse the same holes lol!

    You'll need at least 2" long screws and anchors. The fasteners you'll require might have you going to an actual hardware store, rather than Home Depot, etc. I think you should get expert guidance.

    Have you considered options such as putting up metal shelf supports with multiple screws for individual shelves rather than the rack system? Consider using plumbing pipes floor-to-ceiling rather than relying on support from the walls?

    • Comm
      on May 17, 2019

      Really just drilling the hole for the toggles I bought are a pain and I don't have a bit that's strong enough or wide enough to do the job right now and since I'm unclear as to whether there's actually an asbestos concern, I don't want to be drilling right now and exposing myself to contaminants in the dust. So hopefully when I find out about the asbestos, I can move forward.

      Thanks for your response! Sorry for the choppy responses... it wouldn't let me send you anything larger!

  • Robyn Garner
    on May 17, 2019

    I think my "view" of the damage made me think this was a huge hole! Good luck with the repairs.

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