ᐅ KALLAX Top Panel Curved – Load Limit Exceeded?

Hello everyone, I recently bought a KALLAX shelving unit from Ikea and ordered a matching top board. However, during assembly, I noticed that the top board bends significantly under load. The board isn’t especially long – 147 cm (58 inches) – and according to the product information, it should be suitable for normal use.

My specific question is: Could it be that the load capacity of the KALLAX top board is actually exceeded when I place typical items like books or decorations on it? Or do these visible deformations possibly indicate a manufacturing defect or poor material quality? I would like to know how sturdy these boards really are and whether additional reinforcements could prevent this issue.

Thank you in advance for your insights!

It’s great that you explained this topic so well! 🙂 I’ve had my KALLAX board for a while now and can only say: a slight bowing is completely normal when you put a lot of weight on it. The boards are not designed for very heavy loads, but they are perfectly fine for books or decorations! Just avoid placing very heavy items in the middle area, and everything will stay stable. For extra safety, you can always put a thin wooden board underneath as reinforcement. That makes a lot of sense and hardly costs anything.

Fredlo schrieb:
A slight bowing is completely normal[…]

I agree with that, but we should take a closer look at the material here. The KALLAX top panel is usually made of medium-density fiberboard (MDF) with a melamine coating. MDF tends to sag under high point loads. So if you evenly distribute books across the entire surface, there shouldn’t be any issues, but concentrated loads in the middle increase the risk of visible bowing. If the sagging is excessive, it could also be due to the attachment or the base cabinet not properly supporting the panel.

It’s interesting how people here immediately assume that ‘a slight warp is normal.’ In my opinion, this is not an acceptable condition for a piece of furniture that is advertised so prominently. Why should I settle for unfinished materials that reach their limits under normal use? Ikea could definitely invest more in quality rather than relying solely on design. Those who spend more on brand-name products don’t usually face this issue. In other words, this seems more like a cost-saving measure at the customer’s expense.

I would like to provide a systematic explanation regarding load capacity and deflection:

1. Material: As CHENNE correctly pointed out, MDF does not have high elasticity. It is suitable for moderate loads but not for heavy point loads.

2. Load Distribution: The deformation of the top panel largely depends on how the load is applied. Distributed loads significantly reduce deflection.

3. Support: KALLAX shelves are designed so that the top panel is supported on the sides and in the middle of the unit. Missing cross braces or additional supports can lead to sagging.

4. Improvement Suggestion: Adding an extra strip or a thin reinforcement under the panel increases load-bearing capacity.

Conclusion: A slight bowing is normal if the panel is not optimally supported. However, if excessive deformation occurs, a claim or reinforcement would be advisable.

Connor schrieb:
In other words: this is more a sign of cost-cutting at the customer’s expense.

I understand your point, but my expectation wasn’t that the board would bend under very high loads. I’m more concerned about what counts as ‘normal use.’ I place not only decorations but also fairly heavy books and some electronic devices on the board. If it already shows noticeable deformation under this, it seems to me that it’s close to its load limit rather quickly. MDF boards are generally not known for maximum stability. Does anyone know if Ikea provides weight limits or a maximum load capacity for this?