Moisture affects wood in several ways. As air becomes damper, the moisture content of wood exposed to the air changes. The following drawings represent several situation that can occur with hardwood floors as a result of MAD Wood™.
In a proper installation, the boards stay flat and uniformly tight together all year long, as shown in the diagram below.
In the next example. the boards were installed too wet for the house’s long term environment. The result is boards that shrank as they dried, creating excessively large gaps between the boards.
The third situation shows boards that were installed too dry for the house’s environment. The result is boards that expanded and pressed together hard enough to actually compress into ridges.
The forth example shows boards that have cupped because the air on the upper side is dryer (lower relative humidity) than that on the under side. This can often happen in the summer in houses with vented crawl space foundations.
The last example shows boards that have reverse cupped, or humped, because the air on the upper side was wetter (higher relative humidity ) than that on the lower side. This quite often happens happens in the winter in houses with vented crawl space foundations.