Is acclimation a myth?

When asking about a hardwood flooring delivery, you’ve probably had someone tell you “the wood must sit in the home for two weeks to acclimatize”. This is an old myth from the days when wood wasn’t properly kiln dried. The wood would need to sit in the home in order to actually dry out. Hardwood lumber is now properly kiln dried this is not required.

The Problems with Acclimating Wood Flooring

In most cases this would do more harm than good. For instance, consider the example of a new home. There are thousands of gallons of excess water in the home. The hardwood flooring delivered will be the driest material on site and will absorb the moisture like a sponge. After absorbing moisture the wood will expand. If it is installed at a high moisture level, when the home adjusts to normal living conditions there will be significant gapping throughout. See gapping picture on the left.

Acclimation in Dry Conditions

The opposite will be true if the flooring has been acclimated in an environment that is too dry. It will absorb moisture in normal living conditions and permanently cup. Since each individual board has a different grain pattern, it will expand and contract in different ways, creating width variations. So you may have one end of the board that is bigger than the other making it very difficult to install, especially in wider boards.

How Width Variation Occurs

Here are two boards from the same batch of wood that have been acclimated in the wrong environment