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I recently purchased Granhult from IKEA for my wall shelf. The problem is that my wall stud do not align with the brackets because of the size of my shelf. Can I simply screw the bottom screws into the noggins and use wall anchors for the top screws? The shelf is going to hold books and some legos. Thanks in advance!

Granhult Wall anchor

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  • 5
    What are "noggins"?
    – popham
    Commented Oct 15, 2023 at 22:17
  • 7
    @popham Noggins are are 2x4s used to apply sense to heads, sometimes repeatedly.
    – crip659
    Commented Oct 15, 2023 at 22:37
  • 4
    Nogging, not noggin.
    – brhans
    Commented Oct 16, 2023 at 0:31
  • 3
    Either way it's UK English for blocking (noggin is also a synonym for block)
    – Jasen
    Commented Oct 16, 2023 at 4:42
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    In the unlikely even you could get away with using a single screw, how is it not obvious that should be the top screw, not the bottom? Commented Oct 16, 2023 at 23:24

4 Answers 4

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No.

First off, the top screws take up most of the load. The weight of the shelf + stuff will try to pull the top screws out of the wall, the bottom screws comparatively hold very little actual load.

Secondly, why are your studs not vertical? I'm having trouble picturing why the bottom holes hit a stud but the top screws do not.

Books are very heavy and a shelf needs to be well built to hold them up. Your best bet is to get different brackets with larger vertical members, which reduces the bending torque the screws have to withstand.

Floating or floating-ish shelves are challenging because their fasteners are extremely highly loaded compared to traditional shelves.

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  • My stud finder cannot find my normal vertical studs for some reason, and my outlet is scewed into a noggin.
    – TheCarpe
    Commented Oct 15, 2023 at 22:36
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    See e.g. en.wikipedia.org/wiki/Dwang Commented Oct 16, 2023 at 19:40
  • @TheCarpe That nogging you found will have a stud on both ends. You may be able to knock on the wall to follow it down to the next stud.
    – bta
    Commented Oct 18, 2023 at 1:38
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It sounds like you've found some horizontal blocking (nogging) typically designed to slow down the spread of fire.

At minimum attach the top of the bracket to the blocking since those will experience the greatest stress; Option 1 in attached image.

Even better would be to find a stud and get two screws into it and one into the blocking; Option 2.

Best yet would be to get a shelf which is as wide as your stud spacing and hit all four screws into a stud.

enter image description here

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  • I agree with the last point. The OP himself says that the "size of the shelf" is the reason for the issue.
    – Wastrel
    Commented Oct 16, 2023 at 14:35
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    I was going to say "shorten the shelf till it lands on two studs" but never thought of getting a longer shelf. +1
    – Criggie
    Commented Oct 16, 2023 at 18:23
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The bottom screws are there more to keep things aligned. The top screws carry the load, where the weight on the shelf gets amplified because of the short distance from the top screw down to the very bottom of the bracket. The worst case load amplification looks to be about 300% at one top screw (when all of the load is located at the tip of a single bracket). For something small like this, I would take 300% of the weight you expect and multiply it by a safety factor. I would shop for drywall fasteners that claim to hold this load in tension. It's a pullout load, not a shear load.

Often times when I design something, I'll imagine what would happen if some idiot decided to climb up and jump on, say, my arched trellis, and I'll treat that idiot as the expected load instead of climbing roses. Those brackets look flimsy enough that somebody probably won't try sitting on your shelf, but if you have a pet chimp, then consider anchoring to support the chimp weight instead of the weight of your books.

* For comparison, the AWC connection calculator outputs the withdrawal strength of a #8 screw with 1-1/2" embedment (2" minus a half inch of drywall) at 117 pounds for Doug Fir studs. For 1" embedment (1-1/2" minus a half inch of drywall), it's 78 pounds.

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  • So you visit sites like Darwin awards and hold my beer?
    – crip659
    Commented Oct 15, 2023 at 22:33
  • @crip659, there exist beefier drywall anchor than you're probably used to seeing. "Bullfix anchors" on Amazon come to mind. That and the shelf is 5" deep and 12" across. I will qualify the answer better for small stuff like this, although I thought that the "chimp" bit was a pretty good caveat.
    – popham
    Commented Oct 15, 2023 at 22:37
  • @crip659, and the analysis is predicated on an absurdly conservative load distribution. If you can find a drywall wall anchor that claims to hold the 300% plus safety factor, then use it and you're good.
    – popham
    Commented Oct 15, 2023 at 22:45
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    "if you have a pet chimp" -- Every parent of a toddler has one of these. Commented Oct 16, 2023 at 19:16
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Another option would be to find two verticals, and cut the shelf width so that the brackets aligned with them. Or at least use one upright for one top fixing, and an expanding plasterboard fixing for the other, which will spread out behind the plasterboard. They actually use a setscrew rather than a 'woodscrew', so present a much larger support area behind.

As already mentioned, the top fixings are the weight bearers, so they need to be the stronger ones, but without knowing exactly where the fixings will be compared with the noggins, it's difficult to give a more helpful answer.

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