We’ve already seen what can happen to the surface of wood flooring when it gets water damaged. The drawing above illustrates what happens to wood floor structurally.
These drawings indicate two different types of water damage. The top drawing is one of “cupping” where the edges of the boards become higher than the center part of the board. This is indicative of water that has come up from underneath the board and caused the damage. The lower drawing is the result of water that has come from above the boards and is often referred to as “crowning”.
Both can usually be observed visually, and can certainly be felt by walking across the damaged section of flooring, or by running your hand over it. While in some cases you can tell exactly what caused the damage, in others you cannot, but determining whether the boards are crowning or cupping gives you a good indication of which direction the water is coming from.