ᐅ After installing LED strips, the Kallax unit is slightly bowing – is this normal?

Hello everyone,

I recently installed LED strips on an IKEA Kallax shelf to create indirect lighting. After assembly, I noticed that the Kallax unit slightly bows outward where the LED strips are attached. The bowing isn’t very strong but is clearly noticeable and tangible, especially when viewed from the side.

My question is: is it normal for a Kallax unit to warp or bow slightly after attaching LED strips? The LED strips are glued on and apply some tension to the surface, but I didn’t expect them to affect the entire shelf like this. Could this be due to the adhesive strength, the material, or the installation method?

Has anyone had similar experiences or advice on how to prevent this deformation? I would appreciate any feedback!

Hello,

A slight warping of Kallax modules after attaching LED strips is not unusual, as the material is made of particleboard, which can react to moisture and stress. The plastic film on the LED strips can also create tension if it is applied very tightly.

What can help in this case:

1. Avoid attaching the LED strips too tightly to reduce stress on the surface.
2. Possibly reinforce the back of the shelf to prevent distortion, for example with a reinforcement panel.
3. Ensure even pressure distribution and avoid applying adhesive films over large areas too firmly.

If the warping remains within a normal range and no cracks develop, there is no cause for concern.

Garry schrieb:
The plastic film on the LED strips can also generate tension

This is indeed an important point. Kallax modules are mainly made from particleboard coated with melamine resin, which is not very flexible. If the LED strips are stuck down too tightly with strongly adhesive tape, the material can easily warp due to the resulting tension.

Additionally, the adhesive layer can draw moisture from the particleboard, causing it to slightly swell or shrink. When combined with pulling or compressive forces, this can lead to visible warping.

I recommend attaching the LED strips as flat as possible and without any tension. If possible, limit the adhesive area before installation and stick the strips in short segments to avoid tension building up over a long length.

Another option is to reinforce the back of the Kallax part with a thin, stable panel, for example plywood or MDF, to prevent deformation. It’s important to plan the construction carefully so that the shelf remains sturdy and visually appealing.

I would also like to know: Are the LED strips warm-running or rather cool? Heat can further deform the material, especially with cheaper boards. For warm LEDs, sufficient airflow should be ensured.

kulau schrieb:
I recommend installing the LED strips as flat as possible and without any tension

Thank you for the detailed explanation; that already helps me a lot.

Regarding your question: The LED strips are so-called "cool white" versions with a power consumption of about 4.8W per meter and, in my opinion, produce hardly any noticeable heat. I attached the strips in segments on the sides of the module, but probably a bit too tight.

Garry schrieb:
Maybe stabilize the back of the shelf against warping, for example with a reinforcement board

The idea of reinforcement sounds interesting. Would a thin plywood panel on the back be useful, or would a foil be better? What would be the best approach to do this without significantly affecting the dimensions?

I would like to avoid having to disassemble the shelf and reattach the LED strips, especially since the warping effect is only slight so far. So a retroactive stabilization would be ideal for me.

Hello,

I would like to share a brief guide on how to attach LED strips to your Kallax shelf without causing warping. The curvature usually occurs due to tension forces and exposure to moisture, as mentioned earlier.

1. Preparation:
- Thoroughly clean the adhesive surface using a alcohol-free cleaner to ensure good adhesion.
- Avoid applying the LED strips under too much tension. Leaving about 1-2 cm (0.4-0.8 inches) of space between adhesive points can help reduce stress.

2. Attaching the LED Strips:
- Work in short sections (max. 30-50 cm (12-20 inches)) and gently press the strips onto the surface.
- Make sure the adhesive areas are clean and free of dust.

3. Reinforcement After Installation:
- A thin plywood panel (approximately 3-5 mm (0.1-0.2 inches)) works very well as a counter-support on the back. Attach it with appropriately sized screws to compensate for any warping.
- A simple film or foil usually does not provide sufficient stabilization.

4. Caution with Heat:
- If you are using LED spots or strips that generate higher heat, ensure adequate ventilation or allow enough clearance.

Summary: Warping is caused by material tension and moisture changes. Careful application of the strips and reinforcement on the back can effectively minimize these issues.

If you have any further questions, feel free to ask!

Wow, this topic is really interesting! I’ve been through the same thing and know exactly how annoying such a warping can be!

KUDAISY schrieb:
A thin plywood sheet (about 3-5 mm (0.1–0.2 inches)) works really well as a counter-support on the back.

That’s exactly what I did, and it helped a lot 🙂! My Kallax was completely stable and no longer warped. Plus: You can also decorate the reinforcement nicely, for example with foil or paint, so it’s barely noticeable.

And another tip from me: Don’t let LED strips get too hot, or the finish might warp even more. But with SMD strips, this usually isn’t an issue.

Definitely keep at it! It’s really worth it when the lighting fits perfectly without unpleasant warping!