There are less moisture related complaints with bamboo floors than with wood floors. When considering wood flooring for wet areas such as a kitchen or bath room, bamboo flooring is a good choice. While moisture related conditions do arise with bamboo flooring, like engineered wood flooring bamboo is more stable than solid wood for over concrete or wet area installations. With bamboo flooring moisture problems are usually a site related condition. Frequently a moisture problem is caused by conditions such as water under the structure, leaking pipe, excessively wet concrete or too much moisture in a buildings structural components at the time the floor is installed. Improper maintenance can also result in the introduction of excess moisture.
The major component in many cleaning chemicals is water. Water can have a detrimental effect on bamboo floors which is a hygroscopic material. When bamboo is exposed to air its tendency is to either dry or gain in moisture. The loss or gain in moisture will continue until the material is in equilibrium with the humidity and air temperature. If too much moisture is gained the bamboo will swell and if too much moisture is lost it will shrink. While bamboo is somewhat more stable then wood in this respect, both are affected.
Bamboo is dimensional stable at its saturation point of about 25–30% moisture content. Below this point it begins to shrink until it reaches 0%. As it starts to gain in moisture it expands until it reaches the saturation point again. Once back at the saturation point of 25-30% it again stabilizes.
When bamboo flooring is manufactured it is kiln dried to an average of 8-10%. Bamboo when made into a floor is dried significantly below the saturation point. Once at this point the flooring is expected to stabilize with the environment in which it is installed. Since the floor still has a natural tendency to gain or loose moisture, it is imperative that the environment be maintained at a suitable level.
Bamboo flooring by its nature has greater dimensional stability and less expansion and contraction than traditional wood floors. This stability is further enhanced by its constructional lay up. In regard to moisture bamboo floors out perform solid wood flooring due to its innate moisture resistance and stability with minimal expansion and contraction.
With engineered flooring the expansion will be significantly less. The reason for this is that alternating layers of the laminate are prepared to run in opposite directions. Since they are not all running in the same direction they have a natural tendency to pull against one another, which helps to maintain stability. While the engineered floor is more stable in this respect, equilibrium moisture content still remains critical. The moisture content of wood and bamboo that is in storage or installed at a point below its fiber saturation point has a natural tendency to fluctuate. This fluctuation is a result of changes in the relative humidity and air temperature within the environment in which the material is stored or installed.
Bamboo flooring and engineered flooring are indeed your better choices for bathrooms, kitchens and over concrete as they are more stable for these areas than a solid wood floor.