In order to determine a good definition of water intrusion or what is meant by water intrusion, consider the two words separately.
First consider the action portion or the term, “intrusion”. An intrusion is something that is done by an intruder. Someone (or something) who comes into your room, your house, or your place of business that is not supposed to be there. The intruder has broken in and made illegal or at least undesirable entry. They were not invited and their presence is unwelcome.
Second the object doing the intruding in this case is water. Water that should have stayed outside the building has found a way to get into the building. Some examples of this type of issue include a roof leak or water coming into a basement. Or water that should have stayed contained has escaped into areas where it wasn’t supposed to be. Some examples of this include plumbing leaks or appliance failures. Another way that unwanted, uncontrolled water can damage a building is through excess moisture vapor and condensation.
"In summary, we can say that water intrusion is the uncontrolled movement of water or water vapor into areas in a building where it is unwanted and undesirable."
Water intrusion, moisture intrusion, or water ingress is a serious concern. It can result in significant physical damage to buildings which requires expensive repair and remediation efforts. Additionally the occupants of a building with a water intrusion problem can potentially experience various health problems. That is why it is important to understand, prevent, and/or identify and remediate water intrusion issues as soon as possible to eliminate or reduce the severity of these negative effects.
What are your thoughts on this definition? Is it missing anything? Could it be stated differently? Let us know in the comments.