ᐅ Why do some Billy bookshelf shelves no longer fit perfectly in the unit?

In fact, there are two main causes for the fitting issues described with Billy shelves: material changes influenced by environmental factors, and manufacturing tolerances at IKEA.

Particle boards are hygroscopic, meaning they absorb or release moisture, which leads to swelling or shrinking. This effect is especially strong at the edges if they are not properly sealed. The expansion and contraction can also cause misalignment of the drill holes, making assembly more difficult.

Additionally, the dimensions in mass production, such as with Billy, vary within acceptable tolerances. Minor changes in the manufacturing process or material substitutions can be reasons for this.

One solution can be to adjust the drill holes on the wall and shelf yourself or to make the side brackets more flexible. Sometimes, using longer dowels or modifying the brackets can also help improve the fit.

That’s exactly what I experienced last year with my Billy! I was really frustrated because the shelves just wouldn’t fit properly, even though I hadn’t changed anything. Then I found out that the humidity levels in my apartment fluctuate a lot, and I learned that wood and panels behave like a living material!

A little tip from me: if you leave all the shelves in a consistent, dry place for a while, they will settle and often fit much better afterwards! 🙂 Also, it helps to check the dowels sometimes. Sometimes they turn along and mess up the fit.

Don’t worry, you’ll get it! It’s a challenge, but definitely solvable.

What I would like to add: No matter how carefully you try to fit the shelves perfectly, if the shelf unit itself is not completely level or if the end panels are slightly warped, this can cause issues.

I recommend checking the entire shelf unit for levelness and stability before installing the shelves, and if necessary, using shims or making minor adjustments at the base supports to compensate. I experienced these problems myself, and sometimes small aids are simply needed to restore both appearance and functionality.

Danabla schrieb:
One solution could be to adjust the drill holes in the wall and floor yourself or to make the side brackets more flexible.

Interesting, thanks for the tip. Do you mean slightly enlarging the holes with a handheld drill? I don’t have heavy-duty tools at home, but maybe I could try with a small cordless drill. Is there a recommended procedure to avoid accidentally damaging the shelf?

Also, I like the idea of using longer wall plugs – some of mine are already a bit worn out. Should I use metal anchors instead, or are the plastic plugs from IKEA sufficient?

In general, adjustments to the drill holes should be made using an appropriate wood drill bit that is not too large, in order to maintain the stability of the hole. The recommended procedure is to first mark the spot where the fit is incorrect, then carefully ream the hole with a smaller drill bit. If the dowel hole is too tight, this can cause binding and wobbling.

I advise against using metal dowels, as the material behaves differently and can damage the shelf. The original plastic dowels are properly sized and are easier and better to replace if worn. You may want to completely remove the old dowels and use new, high-quality plastic dowels with the same dimensions as the originals.

If you don’t have a cordless drill, this can also be done with a hand drill, but it is more difficult to maintain accuracy. You should ensure the holes are drilled as straight as possible and not enlarged too much, as this can compromise stability.

Carefully enlarge the drill holes, check the anchors, and monitor the humidity. These are the three most important points. Everything else is overengineering.