ᐅ Kallax screws loosening after a short time – would thicker wood be a better solution?

Hello everyone, I have a Kallax shelf from IKEA that I mainly use for books and some decorative items. Unfortunately, I have noticed that after a short time, the screws holding the back panels and shelves become loose. This causes the shelf to wobble slightly, and the overall stability doesn’t seem very strong. My question is: from a technical perspective, would it make sense to build a similar structure using thicker wood or reinforce it to avoid the problem with loose screws? The standard Kallax wood seems quite thin and perhaps not sturdy enough for long-term use. Does anyone have experience with using thicker wood boards for shelves like this or tips on how to keep the screw connections permanently stable? Looking forward to your opinions and suggestions!

Hello Batuhan, your issue with loose screws in Kallax shelves is indeed a commonly mentioned concern. The standard panels at Ikea are usually 10-12 mm (around 0.4-0.5 inches) thick, often MDF with a veneer finish, which means limited durability when frequently screwing and readjusting.

The wood is relatively soft and tends, due to its lower thickness and material properties, not to hold screw fittings firmly over time. If you plan to build a new shelf or reinforce an existing one, there are a few points to consider:

1. Thicker panels (for example, 18 mm (about 0.7 inches) plywood or laminated particle board) provide better thread grip. This allows you to screw in screws more tightly, and they lose their hold less quickly.

2. The screws used should be wood screws with a larger diameter and good threading, possibly even using insert nuts or dowels for reinforcement.

3. Since the shelf experiences static and dynamic loads (books, movement, readjustments), the type of joint also matters: tongue and groove joints or additional metal brackets can help.

4. Using wood glue in combination with screws can also increase stability.

In short: yes, thicker and higher-quality wood is advisable if you want to achieve lasting stability. How do you plan to use the shelf and what scale (dimensions, loads) are you working with?

Thicker wood definitely helps. You can also combine screws with wood glue to ensure a stronger hold. Also, check if you have used screws with a larger diameter.

I would recommend using furniture-grade plywood with a thickness of at least 18 mm (0.7 inches) if you want to improve stability. Multiplex boards are very suitable for this. Also, pre-drill the holes before inserting the screws to prevent the wood from splitting and to strengthen the screw connection. This helps prevent the screws from loosening over time.

In my opinion, the construction method used in Kallax is also quite interesting. It’s not just the thickness of the wood, but also the type of joints that matter.

Filippo schrieb:
The screws used should be designed for wood with a larger diameter and good thread engagement, possibly even including barrel nuts or dowels for reinforcement.

That’s a good point. Often, the combination of screws and simple back panels without additional bracing is the weak spot. Using thicker boards alone might help, but if the structure isn’t properly braced, the problem remains.

Therefore, it’s important to also rely on reinforcements, such as metal brackets or using Lamello/Domino joints, to better distribute the load and relieve stress on the screws.

To be honest, I consider Kallax and similar budget furniture more of a half-measure – if you want stability, it makes sense to go completely for thick solid wood instead of thin MDF or particleboard.

Josefane schrieb:
It is therefore also important to use reinforcements [...] to relieve the screws.

Exactly. In my opinion, too much is saved on these kinds of shelves, both in terms of materials and construction. A few screws in thin particleboard are not a long-term solution. Thicker wood generally makes sense, but without smart joinery, it won’t work either.