Hard Wood Floor Cupping

The general effect is easy to demonstrate by putting a small strip of paper onto a small drop of water.

Hard wood floor cupping.

Cupping means that the wood that is raised on the edges of each individual floor board. The planks that make up wood flooring expand and contract based on the amount of moisture in the room. See the picture at the top of this post for an example of a cupped floor. Whenever there is too much moisture the wood expands.

If a hardwood floor is installed before a subfloor is properly dried or before the floorboards reach an equilibrium moisture content emc such as before the inside of a building s air is conditioned there is a chance for cupping later on. As furniture and people begin to inhabit the area it will bring about a new level of moisture and. Cupping in hardwood floors is caused by changes in moisture levels whether decreases in the air rh above or increases in moisture from below. This makes the wood appear to be in a u shape.

How to fix cupped hardwood flooring. How to fix cupped hardwood floors. The center of the board dips below the edges. Cupping occurs in solid wood flooring as a result of an elevated mc in the bottom of the flooring compared with the mc of the face.

When the moisture increases the wood swells and then when it decreases the wood shrinks. It refers to a state when the individual wood planks appear to be higher on the edges as compared to the center of the board forming the shape of a cup. The paper will curl up away from the water. Other causes of hardwood floor cupping could include situations such as basement plumbing leaks that allow moisture to migrate up into the subfloor and into the wood flooring or the heat from a wood.