Is there a benefit in replacing/reinforcing the backboards in Ikea cabinet frames?

Question

I'm about to assemble a few Ikea cabinet frames and was wondering if strengthening the backboards would help with anything or would it just be adding work and cost for nothing of practical benefit.

Let's assume there is a single freestanding frame with its back to the wall.

Ikea themselves in the assembly manuals notes some potential issues with the frames such as going out of square or bowing.

From what I understand the part of the frame whose job is to prevent that from happening is the thin, typically supplied folded in half piece of backboard made of laminated particle board. Once assembled the frame is then anchored to the wall (those backboard cutouts near the top in the picture above are where either the wall screws or brackets for attaching to a special rail would go).

That board is either lowered into the recess created at the back of the frame then nailed in place, or slid into the slot in the four frame walls, or a combination of the two (I think this might be the intermediate version before the slotted design was introduced removing the need for using nails).

In the first scenario the flimsy board can be easily replaced by something chunkier that fits within the recess. In the second this won't work as the size of the slot determines the maximum thickness of the replacement board. What one could do is to slide the original backing board in place to form a recess and then put another chunkier board on top, maybe glue them together with melamine wood glue and then nail both to the frame, though nailing may be a little risky since the nails would have to go in at an angle now and there is nothing much to nail to due to the frame material having been removed to make the slot.

Anyway, the point is it's a lot of work, especially with the latest design of the frame. What would reinforcing of the backboard help with?

Answer 1

On a properly assembled and installed cabinet of this type, used within the specifications (i.e. not used to store your collection of lead ingots and vintage ships anchors) the backboard is already more than sufficient. The design of these cabinets is such that the backboard is stressed mostly in shear and tension, directions that it's very strong in.

Think for a moment of a credit card. It would be easy to bend one in half. But despite it being a small square of relatively weak plastic, you won't have much luck trying to tear one in two by pulling on it. The backboard is similar.

The shelving weight is supported mostly by the side boards, not by the backboard. The load on the bottom is supported by the bottom board, again not by the backboard. What the backboard does is keep the cabinet from going out of square if weight in or on it is uneven, and keep the sides from bowing out due to weight on shelf pins. Both of those are relatively small loads, again in the strongest direction for the backboard.

If you ever want to experience this first hand, take one of these types of cabinets, dressers, or bookshelves that is ready for trashing and remove the backboard. You'll find that a tiny amount of weight or strain, or maybe even the weight of the shelf itself, will be enough to send it over into a pile of debris.

In the past I've also run a bead of glue along the backboard as I've been assembling the cabinet to make even more certain it's in place properly. That is a belt and suspenders approach, and completely unnecessary.

Answer 2

IME, Ikea back boards are more than strong enough to prevent the whole unit racking (tilting sideways, the first 'bad' image) and the sides are strong enough to prevent bending ('bad' image 2 and 3).

When I've had a problem, it's because too much stuff been pushed onto a shelf, which bends the back board and allows small items to fall off the back of the shelf.

You can nail/screw/glue the shelf to the back board, but then it's no longer adjustable. I've not tried it, but I'd imagine the ideal solution is to glue a strip of wood to the back of the back board, such that it touches the wall, and then fix the unit to the wall.

Answer 3

Probably yes, but maybe no.

It depends what kind of cabinet it is. And what you want to get out of it.

1. Multi-piece backing board
   Ikea furniture has some quirks - one of them is that some wider units have a backing board made from multiple pieces connected together by the plastic(?) film that keeps it together. They do this, so the piece can be folded to fit in the boxes. This seam is potential point of failure in the future, if the plastic film deteriorates in 10-20 years and cracks, but mainly, it just looks bad. If you want to improve this aspect, you need to buy a new backing board in hardware store, as one piece, cut to size. The thickness is standard, so there is no issue with obtaining replacement, just make sure its cut at correct size so it fits in the slot.

2. Single piece board with corner notches.
   Some models like the one in your first picture have cutoff at corners, to hand them using special braces. If you do not intend to use the braces to hang the cabinets and want to improve visual appeal of not having holes, you can replace the backing board. Or use white insulation tape, works fine too.

3. Single piece slotted boards
   Aka the sliding ones like in Billy bookcase.
   Not much to improve here. If you are not afraid of glue and can guess the amount correctly, do consider gluing them in. Cabinet will be much more stable if the board cannot move in the slot. Otherwise grab a handful of small nails from hardware store and apply them every ten centimeters on the edge - preferably center or slightly off-side to hit the slotted board, just enough to make it not move.
   Ofc ensure the whole cabinet is square before gluing or nailing it.

Additional iprovements:

• If you have wide cabinet and are annoyed by backing board springing back and items falling behind shelves, add some thin strips of wood over the backing board and nail them to the sides of the cabinet. this will keep the backing board from flexing.
• You can add additional rigidity by buying some L-shaped metal flats and screwing them in corners. Or get triangles/squares and screw them in at corners. Adding a diagonal strip of wood from one corner to other corner is slight overkill.
• Do screw your [freestanding] cabinet to the wall. Prevent possible injury from kids climbing up, or earthquakes. Ikea provides a fixing set to every cabinet shell, every door set, and everyone walking in and asking for one.