ᐅ My Kallax sounds hollow when tapped – could it be a material defect?

Hello everyone,

I recently encountered an issue with my new Kallax shelving unit that I would like to discuss, to understand whether this is a material defect or if it is normal for this type of furniture.

When gently tapping the surface, the unit sounds quite hollow, almost as if the interior is empty or the back panel is not properly secured. I have just assembled the shelf and have double-checked several times to ensure all dowels and screws are in place and tightened. Still, it sounds unusually hollow and somewhat “cheap.”

My question to the community: Is this acoustic behavior typical for the material used in the Kallax system (particle board with veneer), or could there actually be a manufacturing defect or poor workmanship causing the hollow sound?

Additional info: The unit was purchased new, and I have not subjected it to heavy loads. The fastenings are secure, and the back panel is complete and straight.

I look forward to your assessments and experiences!

raevita31 schrieb:
When gently tapping on the surface, the shelf sounds quite hollow... The shelf was newly purchased, and I have not put much weight on it.

A Kallax shelf is generally made of medium-density fiberboard (MDF) or particleboard with a thin decorative veneer. A hollow sound when tapping is typical, as the panels are relatively thin and do not constitute a solid construction.

As long as there are no visible damages or deformations, this does not necessarily indicate a material defect. Often, the back panel is very thin and only attached with adhesive tape, which can increase the hollow sound.

However, if the shelf feels unstable after prolonged use or shows cracks, this could be a sign of quality issues.

These shelves almost always sound hollow. This is normal with thin plywood. As long as nothing is loose, everything is fine.

Hey!

I’m very familiar with that hollow sound – it almost seems like part of the usual soundtrack when assembling a Kallax ;-)

The thin particleboard isn’t solid wood, so you basically get a hollow sound built-in by default 😄. The important thing is that the shelf remains stable and doesn’t wobble. If the shelf is rigid, there’s really no need to worry.

Maybe you’re just tapping too lightly? Sometimes you notice the tone more when you pay closer attention, that’s happened to me as well.

Good luck with everything!

GALENKU schrieb:
If nothing wobbles, everything is fine.

Thank you for the quick assessment.

I tested the shelf again thoroughly: it is completely stable, nothing wobbles or feels loose. The panels also do not feel weak at the joints.

However, I noticed an interesting difference compared to the Kallax shelf of my colleague, which sounds noticeably less hollow even when tapped much more forcefully. I wonder if the veneer layer or the panel thickness of my shelf might be slightly thinner or processed differently?

I would be interested to know if anyone has noticed similar differences between other series or production batches.

raevita31 schrieb:
could the veneer layer or the panel thickness of my shelf possibly be slightly thinner or processed differently?

That is possible. With furniture made from engineered wood and veneer, variations in material thickness and wood quality are common.

Ikea produces large quantities on different production lines, which can affect the quality and sound characteristics. If there are no structural defects and the stability is intact, the hollow sound is not necessarily a material defect but rather a manufacturing tolerance.