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I hung 6 Ikea shelves (these ones, which are metal L-shaped brackets with wood shelves on top) on plaster walls using medium-duty plastic anchors.

It was a real issue while we were working. The building was built in the 60s and the wall I'm using appears to be entirely plaster with no studs, no lath, nothing (as far as I can tell). Just solid plaster all the way through.

On the 6h shelf, we thought we'd found a stud and didn't use an anchor. Turns out whatever that was it wasn't a stud. 5 of the 6 are still up after about 2 weeks, but the 6th has fallen.

Ideally I can put the shelf up in the same spot. What I would like to do is fill the holes with spackle (or something else?) and push a masonry anchor into it before it sets, then re-hang the shelf. Is that insane?

If it is insane, can I just cover the holes, move the shelf over an inch, and try again with masonry anchors this time?

Edited to add some pictures:

two holes with a measuring tape for scale a close picture of a hole in a wall made of something crumbly

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    Something has to be behind the plaster holding it up. Plaster is more decorative than structural.
    – crip659
    Mar 24 at 19:09
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    If the wall is "entirely plaster with no studs, no lath, nothing", then perhaps it's actually poured concrete with a plaster skim coat to make it smooth. If that's the case, then a proper masonry anchor would definitely be the way to go. I would suggest though, that if your anchor didn't hold in plaster/concrete, then it's really not going to hold in spackle. Spackle is a very lightweight patching material and has, roughly, zero structural strength.
    – FreeMan
    Mar 24 at 19:11
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    Where in the world are you located? Building techniques vary by country, and what you're describing seems quite odd (but not impossible) for the US, but seems that it may be at least somewhat more common in Europe or other parts of the world.
    – FreeMan
    Mar 24 at 19:13
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    Weren't they using rock lathe for plaster by the 1960s? I would think that you could drill through that easily, and never realize it was there. Of course, I would still expect studs or something else for the rock lathe to be nailed to (probably not screwed in that time period?)...
    – John O
    Mar 24 at 19:22
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    It would be nice to see some pictures of the wall/holes, etc. Hard to just guess....
    – gnicko
    Mar 25 at 0:14

2 Answers 2

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The ideal solution would be to use studs. They are most likely there, but they are difficult to find on plaster walls. I've had the best luck with a magnetic stud finder on my plaster walls. Regular electronic stud finders seem to be worthless here (at least the ones I've tried).

IKEA stuff tends to not be built for standard 16" stud spacing though, so most of the time, this doesn't work anyway. It also limits where you can put things if you want things aligned/centered etc. Another solution then might be to open up the wall and add some blocking for your shelves. This is obviously very involved and messy.

Since the holes have already been enlarged, it seems that they might be large enough now to use a better anchor here. I would recommend a toggle bolt. They usually require a pretty large hole anyway to get them through initially. They're also kind of a pain to work with, but they do hold very well. But you would still want to limit what you put on these shelves. Picture frames are probably OK, a shelf full of heavy cook books might be pushing it.

picture of toggle bolts Image: Tenbergen at English Wikipedia, Toggle bolts, CC BY-SA 3.0

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  • Thank you! If there's literally no space in the wall though (it's solid all the way through) will a toggle bolt work?
    – grenadier
    Mar 25 at 14:00
  • Oh, I missed that part. Your photos look like there is a void at the end of the existing holes. You're right, in that case, toggle bolts won't work.You would probably want to pick up some solid wall anchors that are large enough for those holes (and probably need bigger screws as well. Could also try getting some wooden dowels and construction adhesive, glue the dowels in your holes, cut them off flush, and then use wood screws. Not really sure how well that would hold though. Mar 25 at 14:18
  • I'm not sure what kind of adhesive would be good for gluing wood into masonry - possibly some sort of epoxy. It would take more than a trip to the local big-box store and picking the cheapest epoxy, though. I'd call a manufacturer or two to get their recommendation for something that would work in this situation.
    – FreeMan
    Mar 25 at 15:41
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You must figure out how your walls are built. There is an anchor for everything. No wall is just plaster or just drywall. Something stronger is holding it up.

It's either a stud wall, either wood or metal studs, with one or more layers of things on it. Could be as thin as 1/2 inch drywall or as thick as two layers of drywall over old cracked plaster over fiberboard. Or it's a solid wall .... brick, hollow block, solid block, poured concrete .... with plaster over it, and who knows, maybe with drywall on top of that. You never know.

To put up a shelf like that you HAVE to figure it out, you HAVE to figure out how thick the plaster/drywall coating(s) are, what is behind them, and how to get to the actual wall structure (stud, brick, whatever).

Once you've done that:

  • Wood studs: Use wood screws, long enough to penetrate at least an inch into the wood after getting through the shelf bracket and all layers of plaster/drywall.
  • Metal studs: Self tapping sheet metal screws (same proviso about length) or toggle anchors
  • Brick or block: masonry anchors, into the masonry, with long enough screws that you're not relying on the plaster for anything.
  • Concrete: Tapcon screws

An alternative approach would be to buy floor-standing shelving from Ikea, or buy wall-mounted shelving from a Canadian/US retailer where you'll get long metal rails that can be screwed to the wall in 4 to 6 places EACH RAIL, and then even if you use crappy anchors and don't do a good job with them, the shelves will probably stay up. Maybe.

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  • Thanks. So let's say we know for a fact that these are brick or block and require masonry anchors. Can I use masonry anchors that fit in the holes I already have? Is there something I need to do to ensure that'll work?
    – grenadier
    Mar 25 at 15:14
  • You probably can. The hole, anchor, and screw have to be the right size for each other. For an intro on how to fasten things to brick or block just go to youtube and watch some tutorials. If you already drilled holes, go to the store and buy anchors that require that sized hole, or slightly larger and you can drill them a bit larger. Just make sure your anchor and screw are long enough to solidly fasten to the brick or block and not the plaster facing.
    – jay613
    Mar 25 at 15:47

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