ᐅ Multiplex Panels in KALLAX – Better than the Original Shelves?

Hello everyone,

I recently bought a KALLAX shelving unit from IKEA and am considering replacing the original shelves with plywood panels. I am mainly interested in the advantages and disadvantages compared to the original shelves in terms of stability, load capacity, and appearance.

Plywood panels are generally known to be more durable and look more premium – however, I wonder if the extra effort and cost are worthwhile and if there is anything special I should keep in mind during installation.

Has anyone here installed plywood panels in a KALLAX shelving unit? How do you assess the difference? Are the original shelves really of lower quality, or is their quality sufficient for everyday use?

I would appreciate your opinions, experiences, and possibly advice on which plywood thickness makes sense and how you fixed the panels in place.

Thanks in advance!

Multiplex boards are stronger than the original KALLAX shelves. If you want to store heavy items, it is definitely worth it. I used 18 mm (0.7 inch) thick boards and simply fixed them with small brackets.

The original KALLAX shelves are made of medium-density fiberboard (MDF) with a thin melamine coating. These are sufficient for normal use but offer only limited load-bearing capacity.

In contrast, plywood panels consist of several layers of wood glued together, with the layers arranged crosswise. This gives them higher bending strength and significantly more stability. For shelves that will bear heavy items, they are therefore a better choice.

I recommend a plywood thickness of at least 18 mm (0.7 inches) to optimize load capacity. However, be sure to finish the edges and possibly seal them, as plywood panels are usually unfinished and can absorb moisture.

I completely understand your desire for more stability. I felt the same way when I filled my KALLAX shelf with binders and books – at some point, I was afraid the shelves would bend.

Appearance is also important: plywood looks really high-quality, almost like solid wood, and has warm tones that MDF just can’t match. I was a bit concerned about working with the panels, but it went really well, and now I think it was definitely worth it.

However, I have a question for everyone: How exactly did you fasten the panels? Screws directly into the edges, or would corner brackets be better?

For precise fastening of the plywood panels in the KALLAX shelf, I recommend the following approach:

1. Panel thickness: 18 mm (0.7 inches) is advisable if you want real reinforcement and plan to store heavy loads. 15 mm (0.6 inches) is also possible but less stable.

2. Cutting: The panels should be cut to exact millimeter measurements so they fit well into the cabinet without binding.

3. Edge treatment: To prevent scratches and moisture absorption, I recommend sanding the edges and sealing them with varnish or oil.

4. Fastening: The easiest method is using small angle brackets screwed from underneath to the shelf wall. Screwing directly into the edges of the plywood requires pre-drilling to avoid wood splitting.

5. Load distribution: Depending on the shelf width, an additional central support may be useful to prevent the plywood boards from sagging.

My experience shows that with some care and these measures, you will achieve a significantly more stable and durable shelf.

Surela schrieb:
Screwing directly into the edges of plywood panels requires pre-drilling to prevent the wood from splitting.

I agree with that, but I wonder: Are there any load-bearing or safety-related studies or tests that prove how much stronger multiplex boards really are in the KALLAX compared to the original boards?

The assumption that multiplex is automatically better seems plausible, but it is not necessarily proven. Especially in the KALLAX construction method, the fit and locking accuracy as well as the distribution of forces play a major role.

Perhaps a systematic comparison or a test rig measurement would be interesting before claiming clearly superior properties.