Cork wall tile shrinkage - common causes and how to fix it

If there are walls in your house covered with cork tiles, you’ll already be well-acquainted with their many great qualities – like cork’s natural texture, how it provides excellent insulation from temperature changes and its acoustic benefits. One problem, however, worries a lot of homeowners and installers: cork wall tiles shrinkage.

Like any natural material, cork reacts to environmental conditions, and small gaps between tiles can appear over time, especially in dry environments. Understanding why this happens - and how to fix and prevent it - is important for maintaining a flawless finish and appearance.

What is cork wall tile shrinkage?

When indoor air becomes too dry, cork – which reacts to the surrounding air by absorbing or releasing moisture – can slightly contract, resulting in visible gaps between the tiles.

This is a natural property and not necessarily the sign of a product defect, but it’s important to distinguish between normal seasonal changes and too much shrinkage, which may be caused by a bad installation or unsuitable environmental conditions.

Why do cork wall tiles shrink?

Several factors may contribute to the problem, most of them related to humidity or installation practices:

1. Low indoor humidity

This is the most common cause of shrinkage. During winter months, heating systems make the air drier; when humidity drops below recommended levels - typically under 40 percent - cork can release moisture and contract. Climates with cold winters and houses with constant air conditioning are at special risk.

2. Lack of acclimatisation before installation

Cork tiles take some time to adjust to a room’s temperature and humidity, so if they’re installed immediately after delivery there’s a good chance they may shrink afterwards. Acclimatisation is very simple: it generally just involves storing the tiles flat in the room for at least 48 hours before actually installing them.

3. Incorrect adhesive or installation method

If the tiles are not well secured to the wall, it makes it easier for slight movements to occur, so it’s important to use the right type of adhesive and to apply it carefully, so that there aren’t any bonding issues.

Improper alignment during installation can also make the gaps uglier and more obvious if shrinkage does occur.

4. Substrate and wall conditions

Finally, there can be moisture imbalances or unstable temperatures in the walls themselves.

External walls without proper insulation are especially vulnerable to temperature fluctuations.

Also, ensuring that the substrate is dry, stable and properly prepared is essential to reduce the risk of problems.

Can cork flooring also shrink?

It can, under certain conditions. The same principles apply, as the material is the same, even though there are some important differences.

Cork flooring is often thicker and may be installed either in the form of glue-down tiles or of floating floor planks. Floating cork floors can move as a unit, which often reduces visible gaps between individual planks. Glue-down cork floors, on the other hand, show gaps more easily. Just like with wall tiles, flooring performs best when indoor humidity remains between 40 and 60 percent.

Both cork wall tiles and cork floor shrinkage are typically due to environmental issues rather than manufacturing defects.

How to fix cork wall tile shrinkage

These are a few ways to address the issue, depending on severity:

1. Restore proper humidity levels

The first step is to measure indoor humidity: if it is below 40 percent, consider using a humidifier to bring levels back to the recommended range of 40 to 60 percent. Opening a window or door to allow a flux of fresh air can also help.

In many cases, minor shrinkage caused by seasonal dryness is temporary and gets back to normal.

2. Fill small gaps

For very small gaps, flexible fillers that match the colour of the tiles can be useful; they should be elastic to accommodate future seasonal movements. Make sure to check product compatibility before applying any filler.

3. Replace severely affected tiles

This may be necessary in some cases – when there is a lot of shrinkage and the gaps are too wide – and is often due to lack of acclimatisation or to an improper installation.

A professional installer can assess whether replacement is the best solution.

4. Consult a specialist

If you’re not sure what caused the shrinkage, it’s a good idea to consult the supplier or a qualified installer: they can check environmental conditions, the adhesive and the quality of the substrate.

How to prevent cork wall shrinkage in the future

It’s a commonplace worth repeating that prevention is easier than repair. To minimise the risks, follow these best practices:

• If possible, maintain the air humidity between 40 and 60 percent;
• Avoid sudden temperature fluctuations;
• Let the tiles acclimatise before installation;
• Use recommended adhesives and follow manufacturer guidelines;
• Ensure the wall substrate is dry and properly prepared.

In buildings with central heating or strong air conditioning, monitoring humidity levels throughout the year is especially important.

Frequently asked questions

Is cork wall tile shrinkage permanent?

Usually no: minor seasonal shrinkage often stabilises when humidity levels return to normal. However, severe shrinkage due to installation errors may require corrective action.

How much can cork tiles shrink?

The change in actual size is usually minimal under normal conditions. Excessive gaps indicate environmental imbalances or a bad installation.

Can cork flooring also shrink in summer?

Shrinkage is more common in dry winter conditions: in summer, it’s more typical for higher humidity to cause slight expansion.

Is shrinkage a manufacturing defect?

In most cases, no: it’s simply cork responding normally to the environment. When properly installed and maintained, these movements remain within acceptable limits.

Conclusion

Cork wall tile shrinkage is usually caused by low humidity or installation issues. As a hygroscopic material, cork wall tiles are susceptible to slight temporary changes. The same applies to flooring, with some relevant differences, as explained above.

Proper acclimatisation, professional installation and keeping stable indoor humidity are simple but very effective ways to reduce the risk of any problems with your tiles.