Cupping and Crowning - What's the Difference??

Cupping and Crowning - What's the Difference??

It’s mid-winter and you are noticing your new hardwood floors have gaps between each board. Don’t be alarmed!Seasonal contraction and expansion naturally occurs in anything made of wood, including your floors.

In the winter months, the amount of contraction is affected by both the weather and the amount of humidity in your home. When the weather warms up and there is more humidity in the air, the wood will expand and those gaps will disappear. An environment that is consistently between 60-80 degrees Fahrenheit, and 30-50% humidity is recommended for your floors and also best for your health. Maintaining proper humidity is essential in keeping your floors looking their best.

For general care, here are a few reminders:
  • Dry mop daily to remove dust and pet fur. For a deeper clean, use a cleaner specifically for hardwood floors. We recommend Loba®products.
  • Vacuum weekly to remove loose grit and debris. Be sure that the beater bar is not engaged.
  • Never clean your wood floors with water, general cleaners, vinegar, etc.
  • Avoid damp mopping as this will damage the finish and wood.
  • Clean all spills right away. Never allow them to dry on the floor.

Here are some other conditions that may occur from excessive humidity or unusual wet conditions such as water leaks or flooding.


Cupping is when the edges of a board are higher than the center. High humidity may cause this to happen but it can also occur if water is spilled on the floor and absorbed by the wood.

Sometimes a plumbing leak in the basement can allow moisture to move up into the sub-floor and flooring. The moisture makes the boards swell, crushes them together and the edges become deformed. Cupping can often be reversed once the cause of the excess moisture is corrected. Normal humidity settings in the home may allow the wood to naturally dry and improve over time. If the source is due to leakages, fans may be used to speed up the drying process. Once the wood has dried and flattened out, the floor may need to be sanded and refinished.


In the case of crowning, the center of the board is higher than the edges. This happens when the surface experiences moisture or if the floor was sanded too soon after cupping. We often see this with leaks from a refrigerator or dishwasher.


Buckling is an extreme reaction to moisture that can occur with a hardwood floor. This happens when the floor pulls away from the sub-floor, sometimes by several inches. This condition is usually seen when a floor has been flooded. Repairing the floor is possible in some cases.

Before trying to repair any damage yourself, contact a professional. It may be a matter of adjusting the humidity in your home or using the proper cleaning product. Either way, we are here to advise, service and help you maintain your beautiful floor.
Give Schmidt Custom Floors a call at 970-663-7402.