A rise or drop in a home's humidity affects the moisture content of hardwood floors. The wood usually absorbs moisture when the humidity is high and loses it when it is low. These changes cause the expansion and contraction of wood. And for as long as the expansion and contraction
Extreme humidity changes aren't kind
This is a moisture-related problem that is characterized by the edges of the wood being higher than the center. It usually arises when there is a moisture imbalance – when the wood is wetter at the bottom than it is at the top.
The difference in moisture content causes the bottom side to expand faster than the upper side. And it is this difference in expansion rates that causes the wood to bend upwards with the center being lower than the edges.
Like cupping, crowning is a moisture-related problem that is caused by differences in wood expansion rates. The only difference is that instead of the edges of the wood being higher than the center, crowning is usually characterized by the edges of the wood being lower than the center.
Crowning occurs when the upper side of the floor is exposed to extreme moisture levels. Since the floors are thick, there is almost no chance of the moisture getting evenly distributed throughout the wood. The upper side therefore ends up having more moisture than the floor's bottom. This difference in moisture content causes the upper side to expand more than the lower side, something that causes it to bend downwards with the center being higher than the edges.
However, there are times when crowning occurs simply because of a poorly timed sanding procedure. It usually happens when a homeowner tries to level out a floor that is already
Both crowning and cupping