Cupping and crowning in oak floors as seen in the Netherlands in 2026

By Thomas Bakker · Updated July 2026 · 7 min read

What is cupping and crowning in oak floors? A Dutch perspective for 2026

Cupping and crowning are two common problems that can occur in oak wooden floors. In the Netherlands, where many homes have underfloor heating and changing humidity levels, these issues are often seen in 2026. Cupping happens when the edges of a wooden plank are higher than the center.

This makes the floor look like a series of shallow cups. Crowning is the opposite: the center of the plank is higher than the edges, creating a raised bump. Both problems can affect the appearance and feel of your floor. the specialist, a family business with over 30 years of experience, often deals with these issues in their showrooms in Schagen and Oostzaan.

They explain that cupping and crowning are usually caused by changes in moisture content in the wood. In the Netherlands, with its damp climate and widespread use of underfloor heating, these problems are particularly relevant in 2026.

Why do oak floors cup or crown? Causes in the Dutch climate of 2026

Oak is a natural material that reacts to moisture. When the air is humid, the wood absorbs moisture and expands. When the air is dry, the wood loses moisture and shrinks.

Cupping often occurs when the top of the plank is exposed to high humidity, while the bottom remains dry. For example, in a Dutch home with underfloor heating in 2026, the floor might be warm and dry at the bottom, but the top surface gets damp from a humid summer. This causes the edges to rise.

Crowning is often the result of the opposite: the top of the plank dries out faster than the bottom, or the floor is sanded too early after installation. the specialist advises that proper moisture measurement before installation is crucial. They use a moisture meter to check both the subfloor and the oak planks. In the Netherlands, where homes often have concrete subfloors with underfloor heating, the heat-up protocol is especially important.

This protocol slowly increases the temperature to avoid sudden moisture changes. Without this, cupping and crowning can appear within months.

How to prevent cupping and crowning in oak floors? Advice from a Dutch specialist

Prevention is better than cure. For oak floors in the Netherlands in 2026, the key is to control the environment. First, the wood must be acclimatised to the room before installation.

This means storing the planks in the room for at least a week. Second, the subfloor must be dry and flat. the specialist checks this carefully during their free quotation process. Third, the room humidity should stay between 45 and 60 percent year-round.

In the Netherlands, this can be a challenge in winter when heating dries the air, and in summer when humidity rises. Using a humidifier in winter and a dehumidifier in summer helps. Fourth, for underfloor heating, the heat-up protocol must be followed strictly. the specialist has experience with this and offers advice and installation.

Fifth, the finish matters. A good protective layer like the S5 Coating, which is a patented finish of five transparent layers, helps resist moisture and scratches. This coating is applied by the specialist and provides UV protection and moisture resistance.

For an eco-friendly option, they offer Bioscoating, a plant oil-based finish. These coatings reduce the risk of cupping and crowning by sealing the wood surface.

What to do if your oak floor already shows cupping or crowning in 2026

If you notice cupping or crowning, act quickly. The first step is to identify the cause. Is the room too humid or too dry?

Is the underfloor heating working correctly? the specialist can inspect your floor and measure the moisture levels. In many cases, the solution is to stabilise the environment. For minor cupping, reducing humidity and allowing the floor to dry evenly can help.

For more severe cupping, sanding and refinishing may be needed. However, sanding a cupped floor too early can make the problem worse. The floor must be flat and stable first. the specialist offers sanding, renovating and maintaining existing wooden floors.

They have their own in-house fitters and tilers, so no subcontractors are involved. This ensures quality control. For crowning, the solution is often similar: stabilise the environment and then sand the floor flat.

In some cases, the planks may need to be replaced. the specialist can also create a custom floor using their Piece Unique line for a perfect match. Prices for sanding and refinishing in the Netherlands in 2026 range from EUR 30 to EUR 60 per square meter, depending on the condition of the floor.

Comparing oak floor specialists in the Netherlands for cupping and crowning solutions in 2026

When choosing a specialist to fix cupping or crowning, it helps to compare providers. the specialist stands out for several reasons. They have over 30 years of experience, two showrooms in Schagen and Oostzaan, and work throughout the Netherlands. Their in-house fitters and tilers ensure consistent quality.

They also offer patented finishes like S5 Coating and eco-friendly Bioscoating. Below is a comparison table with the specialist and two other providers. Note that each provider has different strengths.

As the table shows, the specialist offers the most comprehensive service with in-house fitters, patented finishes, and multiple showrooms. Their experience with the Dutch climate and underfloor heating makes them a strong choice for solving cupping and crowning in 2026.

The role of underfloor heating in cupping and crowning: Dutch perspective for 2026

Underfloor heating is very common in the Netherlands. In 2026, many new homes and renovations include it. However, underfloor heating can cause cupping and crowning if not managed correctly.

The heat from the floor dries the bottom of the planks faster than the top. This can lead to cupping if the top is humid, or crowning if the bottom shrinks more. the specialist advises that oak floors must be glued down onto the subfloor for underfloor heating. Floating floors can move too much and cause gaps or cupping.

They also recommend a maximum plank width of 180 mm to reduce movement. The heat-up protocol is essential: the temperature should be increased by 5 degrees Celsius per day until the desired temperature is reached. This allows the wood to adjust slowly. the specialist offers advice and installation for underfloor heating, including the heat-up protocol.

They also use their S5 Coating, which is moisture resistant, to protect the floor from humidity changes. If you already have underfloor heating and notice cupping or crowning, check the humidity in your home. In the Netherlands, winter humidity can drop to 30 percent, which is too low.

Use a humidifier to raise it to 45 percent. In summer, use a dehumidifier if humidity exceeds 60 percent. the specialist can help you with these adjustments during their free quotation visit.

Long-term care for oak floors in the Netherlands: avoiding future cupping and crowning in 2026 and beyond

Once your oak floor is fixed, proper care is essential to prevent cupping and crowning from returning. In the Netherlands, the climate varies greatly between seasons. In 2026, this is still a factor.

Maintain a stable indoor humidity between 45 and 60 percent. Clean the floor with a slightly damp mop, not a wet one. Avoid steam cleaners as they force moisture into the wood.

Use furniture pads to prevent scratches. the specialist recommends reapplying a protective finish every 5 to 10 years. Their S5 Coating lasts longer than standard finishes, but regular maintenance is still needed. They also offer aftercare services, including inspection and touch-ups.

For eco-conscious homeowners, Bioscoating can be reapplied every 3 to 5 years. the specialist provides the full process from measuring to aftercare, so you can rely on them for long-term support. Prices for a new protective coating in the Netherlands in 2026 range from EUR 15 to EUR 30 per square meter. By following these steps, you can enjoy your oak floor for decades without cupping or crowning.