How to mount Kallax shelving to plaster wall?

September 25, 2020 6:04 PM

Help, I bought a 2x4 Kallax from IKEA thinking that it could be mounted 4' up the wall horizontally, and that's exactly what the adorable pictographs on the instructions say not to do! Is there a way for me to mount this safely to my plaster wall?

What kind of super-reinforcing will I need to do to make this weight-bearing and safe for things like books? Assume basic handyperson skills. Or should I return it and just buy a couple 2x2 versions which apparently DO mount to the wall?

posted by oxisos to Home & Garden (16 answers total)

You might be able to get away with it using several standard shelf brackets inside the upper compartments, but that would look really goofy. The problem is that Kallax shelves are not dense enough (ie, you need solid wood) to allow for any kind of inconspicuous or hidden hardware, so I recommend returning it and buying the wall mountable version.
posted by MillMan at 6:43 PM on September 25, 2020 [2 favorites]

If you were going with MillMan's suggestion, I'd want to make sure I had supports underneath the base. The dividers are probably slightly more solid that the paper-and-veneer outside edges, but they won't support the bottom pair of compartments.

Honestly, if I were doing this, I'd figure out whether I could mount a thin shelf that would hold all or most of the weight of the items you intend to put on the shelf, plus the shelf itself, and then affix the Kallax to the wall just to prevent it from falling forward.
posted by sagc at 7:07 PM on September 25, 2020

I am confused. The pictures linked to, show the unit on the ground. Is that what you want to do? If so, that will bear all the weight. The key is putting in a bracket at the top to keep it form tumbling forward. If I recall, my Kallax came with holes for the included brackets. You might need to put some anchors in the wall for the screws, but it should work.

My Kallax units, also 2x4, are currently sitting on the floor length wise, but have been used vertically without the bracket. If you have young children, I would not do that, but if you have most of the weight near the bottom and no one will possibly climb on it, sitting it on the floor without the brackets is a risk, but in my opinion a reasonable risk.
posted by AugustWest at 7:44 PM on September 25, 2020

Response by poster: AugustWest, I want to mount the entire unit on the wall, nothing on the floor. Apparently I saw photos of this somewhere on the web and made some mistaken assumptions when I bought it. The link to the product page is to show the product, not what I am trying to do with it.
posted by oxisos at 8:15 PM on September 25, 2020

Best answer: Seconding sagc. The issue is going to be that Ikea designed the unit to rest on a floor. The dividers and sides are designed to transfer the weight to the bottom panel, and the top transfers the weight to the dividers and sides. Looking at the assembly instructions, the center dividers are just held in with dowels. If you hung it, especially with the bottom unsupported, it would start to sag, which would allow all the internal dividers to loosen, and the whole unit would just start to fall apart.

In my opinion, the only way you could safely put this particular unit on a wall would be if it were mounted on a shelf that could carry the entire weight of the Kallax unit, plus everything that you put into it. The shelf would become the 'floor' that the unit is resting on, so you wouldn't be changing the way the unit distributes the weight. And it would have to be sturdy--if it tilts away from the wall, your unit will want to tip over, and the wall anchors probably aren't designed to support that kind of load long term. Such a sturdy shelf would be pretty hefty and would probably ruin the aesthetic you're going for, or else would likely cost more than the Kallax unit in materials.

Buying the units that are designed to be wall mounted is the simplest and safest solution.
posted by yuwtze at 8:28 PM on September 25, 2020 [11 favorites]

I was thinking french cleat hanger along the whole length of the top and bottom of the Kallax, screwed into studs in the wall, might be strong enough. Unfortunately, I think MillMan is right, it would just pull the hardware out of the shelving unit side instead of the wall.
posted by ctmf at 9:09 PM on September 25, 2020

Fellow plaster wall haver here. I Asked about drilling into my walls recently and was uniformly and thoroughly dissuaded from even trying. After reading up on the vagaries of hanging even sort of heavy shit on plaster walls, I'd worry that when (and I think this is a when rather than an if) the mounted shelves fell off the wall, they'd bring a huge chunk of the plaster with them, and then you'd have a problem that probably exceeds "basic handyperson skills." There are sad and horrifying pics on Google if you want a visual.
posted by easy, lucky, free at 12:54 AM on September 26, 2020 [2 favorites]

We put ours on tall feet to raise them from the floor.
posted by DarlingBri at 5:11 AM on September 26, 2020 [3 favorites]

I think you could do it with sturdy shelf brackets, something like these, 4 on the bottom to support the weight, and 2 underneath the top shelf to keep it from pulling away from the wall. The brackets would need to be anchored into the wall studs. It's challenging to find studs in plaster walls, though. I wouldn't trust plaster molly bolts even if you used enough of them to theoretically support a 300-400 lb shelf+books.
posted by drlith at 6:19 AM on September 26, 2020

If I were going to do this, I'd get a sheet of 1/2" finish grade birch plywood , cut it to match the size of the back of the shelves, paint it to match the wall, secure it to the back frame of the cabinet on all sides using many screws and glue, then use screws to secure the plywood directly to the studs in the wall. Having a structural back panel on the shelves will tie everything together into a rigid assembly.
You can definitely hang heavy things on plaster walls, but you absolutely need to use hardware going directly into the wall studs. This shelving unit is big enough that you should be able to position it such that you'll be able to catch at least two studs and having a sheet of plywood on the back gives you lots of flexibility about where you can put your mounting screws.
posted by Larry David Syndrome at 7:08 AM on September 26, 2020 [1 favorite]

Best answer: I have a few Kallax units - I've even adapted a couple of them in my workshop, so I know how they're made. The outer sides are made of a grid of corrugated paper, enclosed in a thin hardboard shell, with a few reinforced areas where the boards are fastened together.

For the above reason, I would not try to attach the unit to any kind of backing board. There simply isn't a way to secure a load-bearing backing to those outer, thicker panels, because there's nothing solid to screw into. You'd just be supporting the load on some screws driven into a couple of mm of hardboard. They'll just tear out when you tighten them. Or, when you try to mount it to the wall, the back of the unit will just rip off.

Brackets screwed to the unit will also not bear the full weight of the unit. Taller units come with brackets near the top, but those are just to stop the unit from toppling forward - it still needs to be set on a level floor.

I'd also be very dubious about attaching feet to the bottom, because when you put a Kallax in a horizontal orientation (which I'm assuming you intend), the bottom panel is not supporting the side panels - they're screwed/dowelled into the sides of the panel in that orientation. Unless you add a sheet of plywood underneath to spread the load, I think you'd be stressing the bottom panel unevenly, and the design tolerances don't allow for that.

I think the only way to elevate a Kallax above ground level (at least in a horizontal position) would be (as others have said) to build a shelf capable of supporting the unit plus whatever's on it. That's going to require a seriously engineered shelf, because that shelf has to stay completely horizontal under a load equivalent of a couple of average-sized people (assuming you load it up with books). I'm not sure I'd trust a stud and plaster wall to carry that kind of load anyway.
posted by pipeski at 8:11 AM on September 26, 2020 [4 favorites]

We have our Kallax on feet. We have a 4x2 Kallax and have it so it’s horizontal. We originally had it on four feet but it began to sag (we don’t have heavy things in it, just kid toy storage, the sound bar, {tv is mounted above}, our modem, and odds and ends).

When it began to sag we got two more feet and put them in the middle and it’s worked out ok for us. Again, we aren’t using it as a bookshelf or to hold a heavy TV so YMMV.
posted by kellygrape at 9:45 AM on September 26, 2020

Just chiming in to say, as the owner of multiple Kallaxes (including three of that specific size that I use horizontally), they are way too heavy and deep yet flimsy in their own way to wall-mount. Definitely do not attempt it.
posted by limeonaire at 11:49 AM on September 26, 2020

Unless you add a sheet of plywood underneath to spread the load, I think you'd be stressing the bottom panel unevenly, and the design tolerances don't allow for that.

I should have added we used six feet and not four but people do it with four all the time -- the internet is filled with examples, instructions and hardware if you want to google "Kallax on feet".
posted by DarlingBri at 12:56 PM on September 26, 2020

Given the added info provided by pipeski (wow, I though the worst case materials for IKEA shelving would be particle board covered with some sort of contact paper) I retract my suggestion of adding a backing board. It would be sound advice for a cabinet made out of just about any sort of wood, but in this case-- no.
posted by Larry David Syndrome at 3:05 PM on September 26, 2020

A lot of the people putting legs on Kallax units are doing one of two things: (i) attaching them to a board that hides underneath the unit (as in this example), or (ii) putting multiple legs on, lined up with all of the verticals. The latter option still gives you the headache of how to attach the legs in a reliable way. I'd probably combine both methods.
posted by pipeski at 6:55 AM on September 28, 2020