Hardwood floors – cupping and crowning

When hardwood floors get wet you must know what to do if you hope to restore the floors to their pre-flood condition. Cupping and crowning are common results of improperly drying hardwood floors. This type of damage can ruin your beautiful floor.

Here is how it happens:

Water becomes trapped between the wood floor and the subfloor. This is usually caused by water standing for long periods on top of the floor or excessive moisture rising from beneath the subfloor.

Cupping (below) occurs when the bottom of the wood floor is wet and expands relative to the top of the wood floor.

Cupped hardwood floor

Cupped hardwood floor

The biggest mistake possible in a cupping situation is to sand the wood floor flat while there is still moisture in the floor. This leaves the edges of the wood thinner than than the center with moisture that still needs to be removed from the wood.

Normal hardwood floor

Cupped hardwood floor after sanding

As the wood dries completely, the thinner edges recede and leave the center of the boards crowning upward. This is called a crowned floor.

Crowned hardwood floorCrowned hardwood floor


The insurance industry has a long-standing tendency to rip-and-replace wood and tile floors that have been involved in flooding. Modern equipment and techniques make it possible to dry and restore your beautiful hardwood floors to their pre-flood condition. After most hardwood floors are dried they settle into their original position and don’t even need to be refinished.